good beginner corals?

[rocky reef]

hi everyone, this is my first post!
i have a 20g tank, have had it for about 3 months now. water parameters are normal and acclimated for my 2 little clowns. i have about one large piece of live rock, an overhang light, a heater and filter, and im interested in adding some good beginner frags (preferably lps)
i understand that corals have a specific preference for light and flow but as of right now i dont have a flow pump as i haven't had the need to get one but if anyone has some suggestions about corals that prefer low flow, that'd be great
i'd definitely get a flow pump if absolutely necessary for any type of coral but if there's any corals that don't necessarily need it, please let me know!
also, i'm open to receiving any beginner advice for coral care in general :)
thanks in advance!

 

[blaxsun]

Zoanthids/palythoas, green star polyps - those are all hardy and relatively cheap.

 

[vetteguy53081]

Candy cane
Leathers
Mushroom
Xoa
Hammer
Gsp (isolate from other rocks)
Gorgonian

 

[bnord]

add to the above.. Duncan polyp or two

there are some pretty clove polyps for cheap floating around these days