Which 3 That I Should Buy First

Yeah, was actually gonna suggest that you go for the three that you listed at the end!

Sword's a good move; in spite of all the drama over the national dex being cut, my friends who have actually played it really enjoy it.
I can also personally recommend BOTW and Smash, though the latter is more fun when you can play with others irl. Online play is always hit or miss with lag imo.