Does your router support 5Ghz Wifi? And if it does is it enabled? Im not sure what type or router you have but if you have something thats quality and relatively modern then it should. To enable it if it already isnt, go into your web browser and type 192.168.1.1 in the url bar and you should be prompted to put in a user and pass. If you arent try either 192.168.0.0 or 192.168.0.1 if either of those doesn't work, check your router as it might have insight into what to put. Once you're into the dashboard, the wifi options should be the first things you see. You have to go to the 5GHZ option and enable it. Once it is, it should say whatever its named and then 5G after it in your wifi list. If you dont see it even though its enabled, your laptop probably doesnt support it, although that would be really odd as my phone and 2010 MacBook see mine just fine.
Sorry if that was confusing. If it was just get the brand and model number of your router and just type that into google followed by "how to enable 5Ghz wifi"
I hope this answered your question, if it did please hit the accept answer button!