What is the best image editor & creator software which is easy to operate and cheap too?
“Best” depends on what features you need and what operating system you will use. If you just need software for online viewing (not CMYK for print), I suggest GIMP from gimp.org simply because it’s free, and there are hundreds of tutorials online to give you help.
I advise Adobe PS + Illustrator + 3Ds Max. So, good luck, man! 
i would recommend you the adobe products because these are good for the graphic designing. if you’re looking for free then gimp is also an option. But the standard and most famous and easy to use is adobe photoshop. You can also try the illustrator, 3dmax and corel.