Ender 3 first layer printing and adhesion problems

I recently bought an Ender 3 and i can never get the prints to stick to the bed. I always have to use some sort of adhesive i.e glue or/and print with a raft. Any time i try to print straight onto the surface it either peels off/doesn't stick in the first place, or if i try and put the bed closer to get it to stick this happens. Does any body know how i can fix this as its very frustrating having to wasting filament printing a raft for every print and having prints with uneven bottom surfaces from the glue on the plate.