Too many logins to solve problems

First you have to sign into the USACO ‘guide’ then to solve any problems it redirects you to a different usaco website where you have to re-register a new account (this other website doesn’t send an email confirmation). There’s also the ‘training gateway’ but no explanation if you should use the guide or gateway.

That’s because USACO and USACO Guide aren’t affiliated.

Your other two questions are mentioned here: