You might want to join a progress guild or join a community that farms Heroic, maybe as a trial raider.
You have the possibility to create a group and try to kill as much bosses as you can, although most of the time they failed and group falls apart.
You can get invited without Curve if your gear is good enough.
Agreed. The other day I joined a Mythic Skitra PUG, people with Curve didn’t know Heroic mechanics; I wonder why…
Well friend i got curve late because i wanted to do it with my guild, we lost a huge chunk of our raid team due to 8.3 beeing what it is plus my server beeing an empty void, so proggresion even on heroic was rough, in the end my guild died. How i eventually got curve you ask? Well the week my guild died i just created my own group and cleared the whole thing.
It might worth checking out the FailTrain community, since they do raids often and the ilvl requirements are pretty reasonable. Their raids go by a sign-up system as far as I know, so keep that in mind.
They are discord based group by the way, I am not sure if they created an actual in game community.