It's fine as is.
Rover
Sara and I are going to the beach, would you like to come with us?
or should it be "would you like to go with us?"
It's fine as is.
Rover
Have a look at this thread go vs come
Unrelated to "come" and "go," however, is the comma splice.
You need to make this into two sentences.
I'm not a teacher, but I write for a living. Please don't ask me about 2nd conditionals, but I'm a safe bet for what reads well in (American) English.