Desperately trying to improve wifi!

I recently bought a pc for the first time ever. I set it up in the basement in my gaming room. My wifi did not show as an option to connect to the pc so I went out and bought some wifi extender and while it does connect now it is insanely slow. My main router is upstairs. Stupid I know and I can’t move it as I’m not the owner of the house. Also stupid I know. I’m looking for any help in improving my wifi and download speed on my pc. I can’t run a Ethernet cable to my pc. There are millions of products online and in store but k have the knowledge of a newborn when it comes to wifi and internet stuff. Any help is GREATLY appreciated. Thanks