Same as anywhere Mungo, for command you'll have to join the seniority queue, also you will need 500hrs on type with flybe before you are eligible.
Basing depends on demand, SOU is popular so you'll have to join the queue here too, I know of 2-3 F/Os who have joined there having bid for it with only 8 month's service so you pays your money you take your chance.
Exeter is popular too, fair few new F/Os started recently so chances of being given it straight off will be reasonably slim, but again you never know.
CC