Just recieved my fully assembled MK3 and I'm having some troubling issues right off the bat  

Just recieved my fully assembled MK3 and I'm having some troubling issues right off the bat

It looks like the test print included with the printer (the orange and black prusa logo) came out fine. But when I try to print things myself, even after calibration, everything comes out with lines far-spaced when trying the test files included on the SD card, as well as my own files created using Prusa Control with the proper material settings (so far I'm only using PLA).

I've been using Ultimaker machines heavily at a lab for the past few years and I decided to buy my own more affordable machine so I can work from home, and after looking at some reviews I chose the Prusa MK3, which arrived today.

On my first 2 attempts at printing, the PLA warped immediately and is peeling up off the of print bed (I'm in a very small, contained, room temp environment with no nearby air flow.) I've tried to re-do the calibration, but at certain points the display shows nonsense characters and I have no idea what to do from that point on. At first it says to remove the steel magnetic sheet, calibrates for around 10 minutes, then shows nonsense characters so I have to exit calibration. Perhaps my mistake was trying to perform calibration on a pre-assembled machine and it ruined things. I just wanted to re-calibrate in the case things had shifted as it had come all the way from Europe.

I'm hoping I can run a calibration like what appeared when I first started up my machine, as all of the calibration tests that appear in the menu show gibberish characters (not another language, just random ascii characters) instead of words at some point during calibration and I have no choice as to exit as I don't know if it wants me to put the steel spring sheet on, do something with filament, etc.

https://imgur.com/a/Xa3Qa < this is a link to an imgur album showing my print of the prusa logo included on the SD card, as well as the one that was stuck to the print bed on my machine when I received it. Mine is the silver one with the heavily messed up bottom layer, the orange and black one is the one sent from the factory. The same messy bottom layer issues occurred when I tried printing my own simple box models exported from Prusa Control and had to be canceled before they wasted more filament. The last image of the album shows what the calibration display says after it says "please remove steel sheet from print bed". It's just nonsense and I have no idea where to go from here.

Hopefully this an easily fixable settings issue rather than something that will require extensive modification, as the logo included in my box shows my machine is capable of clean prints. I am extremely grateful for any advice.

EDIT: Here's what the first 2 layers of plain flat box prints look like after firmware update and calibration:
Cable connections have been double checked