Most likely a problem on your end, or maybe its steam maintenance on their login servers in your area. Try searching up your problem on the internet to see if anyone else has your issues too, if so, its most likely a login issue. It will probably be fixed soon if it is, if its on your end, try restarting your Router, and your pc.
Need a bit more detail, do you WANT to connect your account to steam? Keep in mind the only benefit from this is that you can log in via steam on the website, that's it