First Time Buyer - mortgage questions

Hi

I lost my dad a couple of years ago and he would've answered (and helped) all my mortgage and house buying questions... so I'm at a bit of a loss and I have some basic questions about mortgages:

1. I'm erring on a fixed rate mortgage, but how long should I fix for? What are the pros and cons? I was thinking about just fixing for 2 years..... but then what happens when that period ends? Do I have to re-mortgage? Am I better off fixing for a longer duration? What happens if I want to rent it out whilst I'm still under the fixed term?

I'm wary of asking banks etc as I always feel they are biased.

Thanks in advance

japmis
(30,female,Berkshire)