Please help - new to printing - pulling my hair out!

So happy I found this forum - hoping someone can help! I have an HP C4240 and I am trying to print some home made trading cards that are 2.5" wide by 3.5" tall. A few issues that I am hoping for help here. I am using photoshop for the graphics and am printing from there:

- Whenever I print, it seems slightly off-center, making cutting them out a little difficult.
- I'd love to print in the upper left corner so all I have to do is cut 2 sides of the card inside of 4. Whenever I try it though, it doesn't seem to recognize the white border around the trading card, and gets too close the edge ... and even then, it is still slightly crooked
- Whenever I'm printing, the graphic gets slightly enlarged that I'm printing. I would like for my printing to be exactly 2.5x3.5.

Any help GREATLY appreciated, thank you in advanced! Heck, if anyone knows of a 2.5x3.5 printer, that would be awesome too!