since you're probably bronze league, just make banelings and burrow them infront of your or your enemies' base and wait until he moves out.
Then select the banelings and tap your X key
that should seal the deal.
Pro tip: 2 banelings ALWAYS kill a marine. so there's no need to stack 10 banelings on one spot, unless you want to fuck up a siege tank, which makes no sense anyways.
Hope this helps