Are you talking about the seams?
Seams are a definite challenge until you get the hang of it. Right now, your helmet actually looks really good. Especially considering this is your first ever helmet.
If you want to get better seams, here are a few tips.
1: Don't use hot glue. Hot glue tends to get choppy and give you unbalanced results. It's great as a filler, but really it's not the best. I find that contact cement works best. You apply the contact cement to both sides of the surfaces to be joined, LET IT DRY, (Like, 5 minutes, maybe) and THEN stick the sides together. It will form a permanent bond instantly, so be SUPER CAREFUL about placing the parts together.
2: Make sure your cuts are clean and crisp. You can only accomplish this in foam by using SHARP blades. Make your cuts one solid motion, avoid sawing back and forth; that will give you jagged edges.
3: Align the edges carefully and press them together. Sometimes progress here will be quick and easy, and other times you'll have to fight the foam, because it will want to pull away from where you want it. Just pull it where it belongs and stick it together nice and slow, and you'll get it.
4: If you want to get a good seam filler, I use kwik seal, as preached by the powerful and all-knowing Evil Ted from youtube.
Follow this guys advice. He is compensated by Barge contact cement and other product manufacturers, which makes him seem a little 'salesmanly', but his methods are great.
Hope this helps!
EDIT: Your helmet does look alright, though. Don't feel too bad about gaps. My first foam helmet looked *aweful*
