I know you're new and shit but do you really need us to tell you which grabs are easy and which are difficult?
start doing safety/bootgrabs with your dominant hand. once you're confident with that start trying them farther back, you'll start doing tails, stalefishes, blunts and all that jazz. eventually you should be able to back mute and stuff like that.
same deal with the front. move up to truckers, criticals, noses (i can't nosegrab to save my live, im too stiff). then mutes and stuff.
it's really just about being comfortable in the air. keep in mind that spinning with grabs is about a hundred times harder than zerospins with grabs. and everybody has difficulty with different things. I can't do a japan unless i'm switch or doing a flatspin/rodeo.
good luck. next time search before you post cause this thread is mad lame. also unless you upload some pics, you have a penis as far as ns is concerned.