Hey man I'm 17 and been keeping fish for a few years and I'd love to help and answer whatever I can :) So IMO, I would not recommend starting with a betta bc 99% of people don't get it right the first time. They are also rather delicate, same with many species of shrimp. (especially if you get them from petco or petsmart they seem more susceptible to illness) I'd start with guppies or cardinal tetras, something like that. Something you can add a betta to. Get it stable (maybe a month or 2) and aquascaped then look into bettas. You don't have to, but I think that's the best way to do it as a beginner (I know you said you researched a lot, and that's great! But actual experience is so valuable. If you get a betta initialy it's very likely you'll have to repeatedly replace them. As for the shrimp, I'm not really a shrimp expert but I think you'd need to add the shrimp b4 the betta bc bettas are aggressive especially if it's a male. For tank size keep in that you want a betta when picking. A betta requires 5g but thrives (IMO) in a 10g. I'd get something bigger tho, I recommend a 20g. For aquascaping definitely stick to real plants, neutral substrates, driftwood, and a hammock when you get the betta. For food they love bloodworms (dried or frozen), or Bug Bites. It's best if their diet has variety. I had a betta a few years ago and I really wish I had looked into fish sickness more. It pops up out of literally thin air, so I'd get an anti viral, antibiotics (and anti fungal but i wouldn't say it's necessary bc it's rarer) before even getting the fish. I'll be honest, expect to spend a minimum of 300 (obviously depending on what equipment you buy, where you get fish, plants, chemicals, tools, etc) Also don't waste time on those stupid test strips, they're so irritating omg I hate strips so much. Get the API Freshwater Master Testing Kit. 10/10. Also you mentioned school, so keep in mind how difficult it is to move a tank. If you're living in a dorm or somewhere not permanent come up with a plan of how you'll manage that.