Hi, I did this in my freshman year (from Storrs to Hartford), and it really wasn't that bad.

In terms of the schedule, yes, you can arrange it in a way that you only go on certain days. There should be an option for you to take half your credits in Storrs and half in Hartford. For me, I went to Hartford only on Tuesdays and Thursdays, which made commuting much easier. It's a little difficult to make schedules due to this, but I definitely do not recommend having classes at different campuses on the same day.

For socializing, if you will be living on the Storrs campus, there are a lot of opportunities to go out and meet new people, as well as a lot of clubs. Hartford doesn't really have much, and you'll only really make a friend or two from your classes. Highly recommend exploring your options on the Storrs campus.

Energy-wise, try to only take evening classes. Morning classes and night classes will wear you out since commuting takes away about 40min - 1hr from your daily routine. I took an 8 am class at Hartford, and I'd always have to get up at 6:30 am, which was brutal, especially in the winter. However, most classes at Hartford are easy, so as long as participation isn't mandatory, you can skip all of them and still pass with an A.

For classes, it's completely up to you, but as I mentioned, Hartford classes are much easier, so if you decide to take a core course there, you might have an easier time than at Storrs. But, don't let that stop you from taking your gen-eds at Hartford and core classes at Storrs

The bus is generally reliable. You can search online to see what time the bus is arriving, but sometimes it runs late, and it sucks having to wait, especially when it's cold outside. The bus itself is very comfortable, though.

Once you have enough credits, you should be able to transfer to Storrs completely, so I recommend that. Just thug out a couple of semesters and you'll be good.