There's some really good ideas here, and overall it's way better than the majority of first maps. I especially liked the bottom section, and the optional gold pile.
One thing I'd say is to avoid gimmicky things like long lines of thwumps. Most people here will have seen that hundreds of times before, and it doesn't add much to the level. Be careful about floorguards too, they need to be sitting on tiles otherwise they run off the screen, like the one in the bottom right.

I mean, its not amazing, but I sure wish more new people would browse maps on here and get some ideas together first, like you did. I've seen much, much worse first maps. Lets hope theres more to come! Welcome to NUMA, Palms.

A great first map for someone! Still wasn't TOO good, but it looked alright, and played alright, if not quite simply. Good thing you didn't do some really nooby things too.