If you're new to vaping, best bang for the buck in batteries is the itaste mvp2.
High capacity vv/vw passthrough battery.
Often obtainable for $40.
Often available as a full kit.
It is box shaped.
It is a battery so it charges via a cable, not requiring separate batteries of separate charger.
It's a passthrough so you can vape while charging.
It's high capacity, so you don't find yourself having to stop and charge often.