To be sure, I can't use " we'll go now or we go now " if I want to say let's go now. Right?
We'll be going now or we are going now = let's go now. Right?
Thanks a lot again.
You are partly right. You can't say "We will go now" or "We will be going now" because "We will be" is for the future, not the present. However, "We go now" and "We are going now" are perfectly acceptable equivalents to "Let's go now".