Espon Stylus 9900 printer help

[Jmp7624]

I just got this printer a few months ago and it's my first wide format printer. I got a orepre good deal so I figured I could make some money with it but I'm have a really hard time printing pictures. I am wanting to print multiple 4x6 pictures but I didn't realize it was going to be so complicated. I really need someone to either point me in the right direction or help with being able to print multiple 4x6 photos on this printer. I have 36" wide paper in it right now but I'm not sure how to create a template or if there is better software to use than Photoshop for this method. I also have problems when selecting the photo sizes with photoshop. I'll resize an image to say 24x36 for a poster and I always get white borders. I have tried searching through YouTube but all I find is videos made in India and I can't understand them. Hopefully someone can help me here.