>>10021591Start watching the 3blue1brown Essence of Linear Algebra series (and maybe his other videos) to get you interested and motivated to do more math. They're really, really well done.
I wouldn't suggest immediately picking up a textbook, it's not likely you'll have the stamina to get very far the first time.
After watching Essence of LA, you should try reading a Linear Algebra book - a good one is LA Done Right by Axler - and maybe alongside it an intro to proofs book. Do as many problems as you can, they're the most important part of a textbook!
You can find plenty of stuff online for free to get you started.