If you haven't finished your story mode, You will have to in order to unlock Coil.

Then, get together a nice group, if you pug it you might have fun, but if you want a kill I suggest you stay with your FC/Friends at first until you are comfortable.

As other suggested, unlocking Syrcus Tower will get you drops of iLvl100, ok not cute but it does the job (it's very easy since pretty much everyone knows what to do - don't forget to state that it's your first time!), and then you will be able to tackle more and more.

Welcome back! ^^