Not to be an ass but AEG stands for AUTOMATIC ELECTRIC GUN so there will be no gas blow back, also this is a very bland post... some things would help
your price range
what type of gun you want (m4,mp5,etc)
and thats just for starters, also seeing as you are just starting i would go for an aeg not gbb (GASS BLOW BACK) because that requires the use of gas and tends to be on the more expensive side and less user friendly.
as far as teams i have no idea but your getting ahead of yourself, find a gun then go from there.