My pc will not run anything.

My pc physically will not run almost anything. My internet disconnects every five-ten minutes and it’s to the point where I cant even run Microsoft Store past the Check Your Connection and what not screen. I have no idea about pcs and can give any information necessary e.g the graphics card which is a NVIDIA GeForce GTX 1050 TI. I have external wifi antennas which are quite close to the internet and i’m not sure if there’s a problem there (probably not since I somehow get 3 bars of wifi, yet nothing still works. I can’t even run the wifi speed test because it brings up one of the many not connected screens. I have no idea how to fix this, i’ve tried many results such as a ‘sfc /scannow’ in cmd and I troubleshooted it and a result that came up says ‘Your computer is trying to use a DNS server that is incorrect or doesn’t exist’ and I have searched how to fix it to no avail. I have had this issue for a LONG time now and have just ignored it and used my xbox but I decided I should probably fix it. I have no idea where the problem is and LITERALLY ANYTHING would help. (Also sorry if this isn’t the correct subreddit I couldn’t find which one to post it in)

Edit: The DNS problem is fixed and I can at least run what I would normally run in the background and stuff like Microsoft Store now. I’m not sure about games or anything yet but i’ll try soon.