New to Germany/Europe

There is so much to see nearby. Black Forest (No. and So.), Alsace, Switzerland (Zürich, Schaffhausen), Bodensee , Bavarian Alps.

No need to go farther for a while.

Germany has lots of Länder-Tickets (all day passes for regional trains in one German state.) Black Forest has a good bus network; trains and buses cheaply available with a KONUS ticket.

I don't have enough experience to suggest specific destinations. I was going to suggest Paris or Berlin but getting to such places would take most of a day. But look at Rome2rio for transportation options for anyplace you want to go. It's not always reliable, and it's wiser to make any actual bookings with the train or bus operator, but it gives you an idea of what's doable in whatever time frame you have. For example, you're close enough for weekends in parts of Switzerland, Alsace, or Burgundy as well as Germany. Kandern is about an hour's bus ride from Basel, where trains go on various routes. If renting a car is possible, that could save you time as well as give you flexibility.

You'll probably get some good ideas from your neighbors and local acquaintances. I'd consider getting a few travel guides. The Michelin Green guide has a lot of the smaller towns listed that others do not list. You might be interested in Tübingen, Basel, Freiburg, & Strasbourg & the Alsace.

Many people on this forum like Titisee. It makes for a pleasant
stroll.

Titisee is cute, but small and heavily geared toward low-impact tourist activities (like a stroll around the lake). Schluchsee, at the end of the same train line that goes to Titisee, is much larger and geared more toward outdoor activities.

Here are some ideas:

https://community.ricksteves.com/travel-forum/switzerland/interesting-town-near-swiss-german-border

Because you don't have a car, the sooner you learn the DB network, and get the discount cards available only to residents of Germany, the better. This national network is as good for seeing the country as the subway is to seeing New York City. I would think you'd also want to research any possible discount airline hubs nearby, which I can't help with. Freiburg is a likely transit center for you. Interior Switzerland may have winter closures approaching. Do you know how expensive Switzerland can be?

If I were in your shoes, I would concentrate on learning how to use the wonderful rail system in Europe, and read guidebooks on the areas on interest. That will help inform you on what captures your interest, and how to move around Europe comfortably and economically. Rick's guidebooks are great on discussing travel skills, but also the rail-focused website "the man in seat 61". Once you know how to use the railroads and get discount rates, all of Europe is available to you.

I can remember when I moved to Nuremberg for work and how excited I was. You take me back to those days.

You've already received lots of good tips for your immediate question.

You can find others right here on this Rick Steves website.

This link to Travel Tips will take you to information on the nuts and bolts of traveling in Europe including sections on Trip Planning, Transportation, Money, Packing Light, Theft & Scams, Sleeping & Eating and much more.

To add to that, the Man in Seat 61 is a great guide to traveling by train in Europe. This is a link to the section on Train Travel in Germany. From there you can explore other countries and aspects of train travel.

Here on the RS website you can learn about things to see and do in many European countries. You can start with Explore Europe and choose the places of interest from there.

I was looking at the map and you are in a good location to go to many fun and interesting places, especially if you take a fast train.

Spending 2 nights really only gives you 1 whole day between them to visit a place. However, if you leave early enough on Saturday and arrive back home late enough on Monday and don't need to spend a lot of time enroute either direction, you can add about an extra 16 or so hours to that.

When I lived in Nuremberg, many people thought I had a lot of time to travel. They didn't think about the fact that I still had to work, get groceries, clean my apartment, do laundry -- all the normal mundane things we need to do no matter where we live.

But, I had a relatively flexible schedule that sometimes allowed me to have a 5 night weekend. Paris by train from Nuremberg was easily doable. From the map, it looks even closer to where you are. Hmmm?

We were in Kandern for 3 months a bunch of years ago. Are you affiliated with BFA? You've gotten lots of good advice already. One place that was an easy weekend for us, we had a car though, was Friedrichshafen located on the Bodensee/Lake Constance. The zeppelin museum is interesting since you are "up for anything." There is a Torchbearers place there that might have available lodging. You can ferry across the lake at Meersburg to visit Konstanz and Mainau Island (castle, flowers, butterfly house). If no car, maybe you could rent a bike.

One thing I didn't see mentioned earlier. There are several train stations in Basel. If you are using the train to visit places in Germany use the Basel Badischer Bahnhof, sometimes just called Basel Bad. Its operated by the German train system, DB. There should be a bus from Kandern to Basel Bad. The locals can explain all this better than me. Enjoy your time in Germany.

Go to a book store and buy books for the area. The internet doesn't answer all questions. Get familiar with some of the hiking areas near by.

'Steph'....female? There seems to be a global Facebook page - Women Who Hike - that is also broken down by state, province or region. They sometimes get together to do group hikes. Also check Meetup groups. Solo hiking in unfamiliar territory isn't always the safest thing. Animals - 4 and 2 legged varieties are of concern. Take a personal tracker if you can. At this time of year, weather can also blow up quickly so be prepared for some self preservation for 36 hrs if necessary.
I would get to Venice as soon as possible and see it before the crowds return.

You've gotten great advice so far so I don't have a ton to add, just to say that this region of Germany has a ton to offer that isn't covered in most English guidebooks. Using a web browser that can automatically translate German will open up worlds of opportunity to you, as will learning to read some German if you don't already! I really adore the Swabisch Alb area, it's a hidden gem. A little difficult to explore by train, but renting a car is also an option for a weekend.

If you plan on exploring the Stuttgart area, let me know, I'd be happy to show you around. In addition to Europe's best car museum (even if you don't like cars, it's great), there are palaces, vineyards, castle ruins, and impressive medieval cities all within 20 minutes train ride from Stuttgart's center. Feel free to PM me for more info on the Stuttgart region or just general SW Germany travel questions!