Trying for your first baby or trying to have another one?

I’m TTC my first and I’m finding it really difficult because I don’t even know if I can get pregnant or if there’s an issue with my partner or not, because I’ve never been pregnant and he’s never gotten someone pregnant, and it’s really taking a toll on me, so it got me wondering if it’s worse trying for your first or another baby, because at the same time, if you’ve already had one, particularly with the same partner, you know you can get pregnant so I’d imagine it would be frustrating knowing that but it hasn’t been working out