How to lock Mirrors?

My apologies if this is the wrong sub to post this! I haven’t officially started witchcraft yet but I’ve been researching a lot, one of my problems is that I have two huge floor length mirrors in my bedroom that i cannot move or cover with a cloth. I heard they can act as portals and let harmful things in. Is there a way I could lock them without covering them? Or perhaps it would be best for me not to start witchcraft in the first place. I do feel this crippling feeling of being watched whenever I look into the mirror so it may already be causing problems lol. This is probably a very silly question but i felt a little nervous and thought it would be better if I asked. I hope whoever reads this has a lovely day<3