I second having a decent 50mm equivalent lens for starters, they’re pretty versitile and compact.
I personally quite like being constrained to one focal length, I feel like it really taught me to be more deliberate about my positioning, framing and composition, but you’ll have to figure out whether that’s a style of photography you enjoy.
Having a zoom for the flexibility is definitely also nice and fun to try out and invaluable in some settings
In the end, I guess it really comes down to what you end up taking photos of, and which approach is more fun to you.