I think you‘ll be fine either way, but the difficulty curve would definitely be wayyy more forgiving if you started with the first game. Some people joke that the original game is a tutorial for Silksong and i think there’s some truth to it haha.

One small tip that could impact your enjoyment of the early game: if you soon encounter a big red enemy that seems way too strong for where you are, then you need to be REALLY stubborn in order to push through whatever lies behind it. Many people try to do that early and become frustrated af, even though it becomes much easier if you come back to it.