London- double question.

Answer 1. Southern Rail direction Victoria station, get off at Clapham Junction, change to train to Waterloo Station. 45 to 55 minutes, 15.50 GBP anytime fare. http://www.nationalrail.co.uk/
Answer 2. Don't know.

Without knowing exactly when you are arriving, train to London Bridge, the change for the Jubilee Line to Waterloo.

It's an 20:00 arrival. The hotel is a premier Inn Waterloo.

For local restaurants I mean nothing touristy. Where ever the best places are to get the best local cuisine. I hope that helps

There is an excellent walking food tour in the London Bridge area (take public transportation to get there) that includes some interesting sight-seeing as you walk with your small group and sample British food in places that the locals love. It is given by Secret Food tours. www.secretfoodtours.com/london/london-bridge-food-tour/ Everyone is friendly, the group is small and intimate, and you'll try all kinds of delicious British foods, beverages, even English chocolates!

For walking tours, the London Walks Company is the best! Many different themed walks...check out their website: www.walks.com

Before I depart for London I always peruse some food blogs.

Favorites are Londoneater, Londonfoodie and Pickyglutton.

Usually find one or two new places to try when I'm there.

Thank you all for the help. Should I purchase my train ticket ahead of time? Or will I be fine to buy it when arriving that night?

You will be fine purchasing when you get there. For the price of the ticket, not much advantage buying ahead of time plus you can not count on a specific train/time.