Which rail pass is best for 10 days in Scotland and England?

very vague, can't really be answered. We need dates and itinery. But yes, it may be be cheaper to not go for a pass.

Check the prices of your intended trips on this website. Be careful with the dates and be attentive for slightly earlier or later departure times. Compare it with the cost of a pass. You'll probably find that advance-bought tickets is the best deal.

Thanks. I'll be more specific.
We will be traveling from Edinburgh to Inverness on September 28, then from Inverness to Glasgow. Hope to travel down the East coast of England, to Stonehenge, across to Norwich and up the West coast, back to Edinburgh. We only have 10 days and are afraid to drive on the left side, so need trains.
Would it be more cost effective not to purchase a pass?

Would it be more cost effective not to purchase a pass?
First thing you have to do is to look up the prices of these journeys on the train planner of National Rail. Without that you can't know whether a rail pass would be cheaper.

Okay, it looked like you need a little help, so I tried.....
You still have not been specific enough about your dates and destinations. When you are comparing point to point tickets you have to have destinations, dates, and times in mind that are specific.

I took your list from above, put in random times during your date period and came up with an answer that you would be better not to buy a rail pass if those are the only trips you are making. You may want to put in your specifics to confirm .

I would suggest a "Two Together Rail Card." This card costs 30 pounds but will save you 30% off of your tickets. Here is a link to the information about it

https://www.twotogether-railcard.co.uk/?nreTrack=twotogetherrailcard

You can go ahead and buy your tickets in advance before you actually have the railcard. Make sure you include that you have the "Two Together" card to any ticket purchase you make online. Then, when you get to Edinburgh, simply go to the ticket office at the railway station and purchase the Two Together card. You will need to be prepared with two passport type photos (1 for each of you). They will sell you the pass and then print off all the tickets from the reservations you have made. This shouldn't take more than 10 minutes. You will need to show the pass and the tickets to the conductors on the trains.

if it didn't include Stonehenge I'd have guessed this was an itinery for a railfan who wanted to exerience the different trains. 5 travel days of between 4.5 and 7.5 hours journey time each in a 10 day visit? You could fill 10 days and not leave Scotland.

Also the itinery seems to confuse the east and west coast routes. Glasgow-Stonehenge is west (with a 15 second view of the coast) and Norwich-Edinburgh is east (where you might get 15 minutes view of the coast).

Advance tickets especially with a 2 together railcard would probably be cheapest but it's a lot of organising for relatively little time spent on the ground.

Thanks to everyone who has replied so far.
Does anyone know if there is Uber of Lift service in Inverness or Edinburgh?
I know I sound like a lazy American, but I'm 70 years old and have never traveled in Europe or the UK before.

There certainly are taxis in Edinburgh. Do you object to taxis?
You can make life easier on yourself when you are relying on public transportation by choosing the location of your accommodation carefully. For example. The Premier Inn York Place in Edinburgh is located at the last tram stop from the airport. You walk outside the airport, step onto the tram and then step off of the tram at your hotel. It was a nice hotel and I can highly recommend it.
5 minute walk (or short taxi ride) to the train station.

Do pay attention to what people are saying about the length of some of your trips. Make sure that this is the pace and distance you want to travel. If it is, go for it. If not, see if you can rethink your plans a little. I can see why you are trying to fit in as much as you can when it is your first trip and you really don't know if you will be back soon. However, a few things well done will probably be the better memories for you.

BritRail Passes (to buy here) come with senior discounts, or there is a Senior Rail Card (to buy there) that gives discounts on each train ticket you buy (if you don't have two people for the Two Together card). All are described at https://www.ricksteves.com/travel-tips/transportation/trains/britain-rail-passes.

The BritRail Pass offers a lot of flexibility if you don't know your exact train routes but do know that you want 4 days of train travel covered during your trip (during a one-month window). This version of the pass costs [edited] $256 for a senior in Standard Class. I would be happy with the value you'd get out of that when crossing much of the country. The next option, pricewise, is $290 for 8 consecutive days, if you want more than 4 days on trains but also will spend a day or two in Edinburgh on each end. Passes have to be delivered to you at home before you go. Optional seat assignments are free to make in train stations up to a day before a trip.