You haven't chosen a simple pattern to do. It is "easy" because it's only combinations of knit and purl stitches, but having to switch back and forth gets confusing. I've been knitting for a long time now, and I just did a project that I had to rip out three times because it was a combination of K/P on each row. Don't feel bad over this!
One trick is to print out your pattern and use a sticky note under the row you're on to mark your place. If I have to count rows, I will make check marks for each row finished. It helps a lot.
Good luck!
