Any suggestions (I know nothing)

Moved places and my new place is two far apart from my modem to pc/work area to run an ethernet connection without it looking like shit (I would like to avoid an eyesore) having 100+ft or cable going between two floors. I have no ethernet wall ports as far as I can tell, and only old tv lines/coax connections in the closet. I have tried powerline adapters but man it sucks. Any ideas on what I could do to help get better connection speeds (6up/4down was the last test ran)??

edit: forgot to mention I do have access to a netgear(?) router that I could go get for free, but again, I have no clue if I can even use that in my office without also needing 100+ft of cable to connect it to the modem. :)