New to saltwater

Hi! I have had a lot of experience in freshwater but I have always loved saltwater.

I was thinking about eventually converting one of my 20g tanks into a saltwater environment (nothing fancy, just a couple small fish and live rock). Nothing bigger- my other tanks are happily occupied and I don’t have space for more.

I’m just looking to start a conversation about possibilities, and am looking for advice on stocking and how to transition.

And of course I’m also looking for some new friends who know more about this than me!

Thanks :)