confused and not moving till...

I'm knitting, for the first time, some initials. On circs.
Let's say, I have an A and a B, side by side, 2 dishcloth patterns.
After I knit the first row, of the a and the b, do I then begin by knitting
the b instructions, and then the a?
If I go back to the a, I'll join the yarn and make a circle, which I don't want to do.
So, go forwards, and then backwards,
and then forwards, again?
I'm so confused about this, and afraid to make a mistake.