Refilling water after winter

Evenin all !
I want to fill up the water tank prior to using the MH after the winter drain off.
Is there any set routine or just fill the tank ? I'm thinking about how does the water get to the Truma heater ! How to avoid airlocks etc.

Any and all advice welcomed.

Something similar, I don't start bleeding the system until the tank is at least half full, I leave the heater dump valve open until I get water flowing, then close it, and then bleed all the cold water taps and the shower first, then go around the hot system.