Just use a razor to scrape off the print stuff on the print bed. Wipe clean with isopropyl alcohol (highest you can get), and then put a few layers of hairspray once heated. Pick up a paint scraper from the hardware store and sharpen it. Use this (or a razor) to remove prints in the future.
About printing -- I know I'm not giving you the answer you want, but this is the answer you need: drop another $35 on a raspberry pi (unless you have one), and setup octoprint. I've added a link to a tutorial below:
Octoprint allows you to print over the network, check the status on your prints with your phone, remotely stop/start prints, view prints with a connected webcam, update firmware, etc. It's just gonna make your life easier. One note, SD cards connect through the screen, and sometimes the AUX connectors are removed to make way for other hardware features like SPI mode, etc. The previous owner may have disconnected the SD card from the board because he/she was using octoprint. Just a thought.