I'd guess that is a condenser microphone. Those things pick up a lot of crap, if you let it. Crap is sound bouncing off of untreated walls and other surfaces and coming back to muff up your nice clean studio sound. Maybe setup a little temporary mic booth, like somebody already mentioned. If you can't find a closet with a lot of clothes in it, maybe rig up an area where you can hang blankets around you, making sure there are no open areas to let the room sound filter in. Thick blankets all around and even on top, that will stop any of the room from coming in. Then it's just you, the guitar and that condenser mic.
That screen on the mic is so you can get closer to it, with your vocals. Don't get too close, but there is a distance that will sound great. Experiment. If you have to do both guitar and vocal at the same time, see if you can get another mic on the guitar. Same blankets, same recording booth effect, and you might get a sweet spot for that sound, too. The thing is, no background noise for that condenser to pick up, leaving just your voice and your guitar in a clean recording.
You are limited with your setup, if you must track both guitar and vocal at the same time. Ideally, that's rarely done. There's bleed from vocal in the guitar track and bleed from guitar in the vocal. So, you can't adjust either track after being recorded, without affecting the other. That puts more pressure on you to get it perfect the first time, limiting you even more.
Experiment and experiment. Move the mic up, move the mic down, closer to you or closer to the guitar. When you are limited in your situation, that's just hurdle to overcome. Deal with the room, first, then experiment with mic placement, next. One thing at a time, and you will eventually come up with a situation that doesn't sound too bad.