Hi
Welcome to the forum and shortly, to Bern!
Just to answer your question about Hinerkappeln - it is not that far out of the main city but not very convenient if you will be relying on public transport alone. There are about 3 buses an hour but this dwindles down to one sometime after 10 pm.
For a short stay, it would probably be better to find a place in town. As you will be connected with the university, there should be accomodation available through the university contact board. It would also be better for your social life. However you can also look at
www.anzeiger.ch or
www.immoscout24.ch where for rent accomodation is listed. The sites are in German so if you will probably need help navigating these if you don't speak German.
If you have any questions about Bern, feel free to ask,
Greetings
Starbug