Quote from: jphelps on October 13, 2020, 08:09:01 AM

after putting in stratum+tcp://stratum.slushpool.com:3333 for the URL, my user, and a random password

I am rusty too, but at Slush you may need username.workername (I don't know how it handles missing worker). https://slushpool.com/help/bitcoin-setup/?c=btc
Since tell "Auth Failed" I'd go by this first (also log in and create a worker).

But you may also have surprises on low hashrate, but that may translate in more disconnection than useful hashes.