New Player - help appreciated

Hello guys, today I decided to download FEH and start playing it, I already love the game, but I‘m kinda overwhelmed.
I played gacha games before, so I‘m not new to the genre, yet there are so many different heroes and I‘m absolutely clueless.

I googled a bit, but didn‘t find the answer i was looking for, for the two free 5-star heroes i got Lyn and Veronica, but there are so many different banners up, and im wondering for which heroes/banners I should go for?

Or is something big coming up worth saving orbs?
As i said i only got Lyn and Veronica and starting to play Story soon, knowing what to pull might be advantageous!

Thanks in advance!