How do I form my own matchmaking group as I would like help in doing some missions in tier 1?
You can access a matchmaking menu from the map screen and open up your game during a mission, or you can go through the social bit in pause menu to send out invites to friends/clan etc.
What is recalibration all about, I am sure I tried this but I felt the weapon was not as good as it was? I suspect I am doing it all wrong though.
Re-calibration is about swapping talents and stats from other pieces of gear onto a desired piece of gear. Very handy for getting specific stats or perks on your equipment when creating a build. I'd recommend watching some videos on youtube as they'll be able to explain it much better. It's pretty important once you're at endgame.
It also raises the GS of the item somewhat which leads into the next point
How do I increase gear stats as I have been told that they re not high enough on occasion?
You have to equip or keep an item that is of a higher GS in you inventory, items will then gradually start to drop with a higher GS than the stuff you have. Re-calibrating items also boosts their GS a little so it's worth messing around with the gear you have to give you a little boost.
It's then a case of rinse and repeat all the way up to GS 500 so don't become too attached to the stuff you have right now.
I gave a green circle flashing round the Campus but have no idea why, it might have something to do with the drone controller at the White Hiuse who mentioned a mission which I did not note?
It could be because the settlement is blockaded? If the settlement icon is red and you can't fast travel there that means that it has been blockaded by the Black Tusk. You need to hover over the icon and see what it is linked to on the map, clearing that activity will then free up the settlement and open up fast travel again.