download the adobe trial version which is same as full version but has a 30 day useage period and then unlock the full version by looking for a serial number on the internet.
Serial numbers are easy enough to find with a simple google search or sometimes they get listed on youtube.
Obviously this is illegal in most countries so doing this is at your own risk.
GIMP as stated by the first responder is a fairly good package with much better options than MS paint and it is free. I have used this quite a lot in the past before i got the adobe master collection and it is easy to use
