I think this is my last obstacle. All wires lined up and last minute uncertainties have emerged.

I have a circuit breaker for between the mppt and battery.. and one for between the solar and mppt controller

So.. having never wired up a circuit breaker I want to check something out. Having difficulty finding such basic info on google

1) I am thinking that I only need to put the breakers on the positive wire that runs from solar to mppt... and then from mppt to battery. Is that right? I have a diagram that confuses the issue which appears to show fuses on both positive and negative wires coming from the panel.

2) Next Q is regarding whether it matters which end of the breaker I put a particular cable. I intend to keep the flow of electricity going throught the breaker from top to bottom...
I am thinking that I will feed the cable carrying power from the panel in to the top of the breaker.. and the cable leaving the breaker at the bottom then going to the MPPT. Then from the MPPT in to the top end of the next breaker.... then the cable coming from the bottom will go down to my positive terminal on my battery.
Does that sou about right?

3) my neg cable will go from solar straight to mppt. Then mppt straight to battery. No breakers on that line.

Tips appreciated!