Don't take this wrong but, you don't know enough about electricity to even start the planning stage. There is A LOT of information about solar on the internet, some good, some bad and some dangerous. No one is going to do your homework for you.
Check these out.
https://www.youtube.com/channel/UCoj...q8kmJme-5dnN0Q
https://www.diysolarforum.com/index.php
Solar panels produce DC voltage, your MPPT controller, if properly sized, should take care of the battery charging part. Batteries are DC. There are many things to consider such as circuit breakers, fuses, correct size wiring, correct size solar panels, correct size charge controller, etc.
If all you are TRULY going to do is charge laptops and cell phones there is NO reason to invert to AC. Everything on your bus is already DC. Your phone and laptop are DC, there are adapters available, to change to the correct voltage, to charge them from 12V DC.
If on the other hand you want to use anything that plugs into the wall outlet in your house, which is AC, you need an inverter.
Inverter, changes DC to AC.
Converter, changes AC to DC. A battery charger is basically a converter.
Your diagram isn't necessarily wrong, it's just missing a lot of pieces. Without knowing a lot of specifications about the equipment you already have, the only thing I can tell you for sure is that speaker wire is no where near heavy enough, or the correct kind of wire for that purpose. Wire gauge gets discussed ad nauseam on many RV,solar sites. READ them until you understand it.
I'm not trying to discourage you, it's just not possible to answer your question with the information you gave.