my little Oreo had worms when we first got him, this is how he almost died!
round worms are contagious.. but humans will only get them if you literally ingest his poop

but do wash your hands to prevent anything.. you know just to be safe.
oreo had both round worms and tape worms.. soo i know about worms!

not fun!
to answer your questions. no you don't have to stop holding him, kissing him won't make you get it unless he's eating his poop. and keep him away from the grass for now