Pair of not native english speakers looking to try pbp rpg
Hi! Welcome to RPoL!
Yes, this is the place to post for beginners/newbies... where to ask the questions you asked.
As far as I know, there isn't any way to filter the Search engine for beginner friendly games. The best option is probably just putting a post up in GMs Wanted, stating what game you want to try and that you are a beginner at PbP.
Of the games you are looking for, D&D 5e might be the easiest to get your feet wet as you wouldn't really have to learn a new game just yet. Once you are comfortable with PbP.
Freeform games are probably the best for pure writing. On RPoL, I've found that running combat can be somewhat tedious and time-consuming, and there's not a lot of ways to write or role-play them... just number-crunching and dice rolling.
As with most RPG systems, it isn't the game itself but the way the GM runs the game. If he's heavy on role-playing and character interaction, then the rest is just incidental. For example, I'm running a Pathfinder game for two players that's 95% role-playing, 4% dice rolling and 1% combat. It's been a lot of fun.
I'm not all that familiar with other PbP sites, but apparently they are out there. A google search for play-by-post games is your best bet.
Any other questions, just ask!