is their any indicator after liberating an outpost that their are side mission's or do I have to go to the cabinet in each outpost to find out if I had any side mission's or not also do I get more side mission's from outpost's through out the game or does each outpost only get 2 or 3 mission's and once completed that's all the side mission's you get from that area

There is a little icon on the map that shows where you start side missions. And I am pretty sure each stronghold only has 2 -3 missions.

If I recall correctly, there's always little terminals near the exits of each stronghold that give you the missions. They're always on the map as well. They are not very fun or offer much reward, so unless it offers a payout for a weapon you use I suggest just passing on them.

Yeah, there are terminals in each base. There will be icons on the minimap over them if there are missions available.