They must meet with the other countries, work out the details and agree to it, finalize the treaty into a bill of sorts, and the Senate must confirm it with a vote of 2/3. Pretty cut-and-dry.
No. The Senate alone votes to ratify treaties.
The Congress
Congress
The US Congress needs to approve treaties the US becomes parties or signatories of. I'm not sure what you mean by UN treaties, however.
The president can make treaties, but Congress must ratify them.
Treaties are ratified by Congress, in the US.
Only Congress.
Only congress can.
Congress can
The Congress has to agree with treaties. If they don't it cannot be made.
No, it cannot. The power to make treaties with foreign countries is expressly reserved to the president under Article II of the US Constitution. The only role Congress plays is that treaties are subject to the advice and consent of the Senate. Note that "Congress", (i.e. the Senate and House of Representatives together) does not have a role in approving treaties. Only the Senate has such a role.