Invite to what?

[Keydah]

If you see a specially-named level 50 monster on the map you're on that has a blue (non-aggroable) symbol, it's a B rank. You should shout its name and position for anyone searching for it for their weekly, so that they can find it more easily.

If you see a specially-named level 50 monster with an orange (aggroable) symbol, shout its name and position too so that people can pass it along to their hunt linkshells. If it's a huge one, it's probably an S rank.

If you're unsure of what it is, you can check [this] page.

this is only when you reach lvl 50? you can't participate at low lvl?

You can participate in A & S rank hunts, and you should receive allied seals (the hunt currency), but you will die every single time something hits you if you're below about 40. That's just an estimate...I've seen level 5-20s do it, and 45+, but never in between.

So I'm not a new player but I'm new to hunts (never bothered with them in ARR), I did all three quests so I have access to the dailies and the weekly B rank now.. But how do get access for S and A ranks? Or do those count even if I don't have a bill for them? Forgive me if these are noobish questions but like I said I am a newb to the hunt lol

A and S ranks aren't weekly or daily or anything, you just do them when they spawn. You will never receive bills for them. Tbh, I don't know how Heavensward ones work...I'm only 56 right now.