What you should do is start a thread in the Canadian regional section: https://www.stromtrooper.com/forumdisplay.php?f=33
You'll get lots of advice there on route planning through BC.
There's all kinds of variety in terrain. My advice is to take the coastal route northwards (Olympic Peninsula in Washington and Vancouver Island in BC) and the interior on the way back.
Bella Coola is on the coast at sea level. It's a tiny native community at the foot of some really big mountains. As you head inland from Bella Coola, you climb an extremely steep road to the top of the Chilcotin Plateau and then on to Williams Lake (a town not worth hanging around in). It's worth hanging around in Bella Coola though for a day and learning the history of the road before riding it.
As for wildlife, anywhere in BC you have to watch for deer and bear and the like. If you plan to camp at all, learn how to avoid bear and help them avoid you. There are lots of Grizzly around Bella Coola, especially when the salmon are running (later in the fall).
I've had more close calls on the road with bear than with deer. Dusk and dawn are the bad times to travel, same as anywhere. Probably, though, the biggest problem you'll have with wildlife are the mosquitos.
It can be cold in June, especially at elevation. It could be hot, though, so be prepared for either case.
Most of what you'll find interesting in BC are the roads and vistas rather than the towns.