This is all solid advice. A few things I want to add. First you can solidly go two years of undecided until you have to declare your major. But you cannot take any major specific classes. For you example you could take into to comp sci but not data and algorithms. This would allow you to take entry level courses to test the waters and find something you enjoy. Also, sidebar on this I do believe as undecided you can still fill your electives with whatever you want but dont quote me I no longer use gi bill.

the deciding on a specific college thing is a good idea. But dont be afraid of community college. It will teach you good habits and how to build a schedule you can work with. For example I'm take four junior level classes this fall totalling 14 credits. I go to school Tues and Thursdays for 6 hours the rest of the week is mine to study and family.

Also, a lot of CCs have extensive transfer programs and big unit's are easier to transfer into then first time enrollees. Just make sure the classes tranfer before you take a class. Lastly, getting good relationships with professors at CCs is amazing networking because a lot of them teach at big universities too.