What level do you start training at future ereve?

I was wondering this.

Also was wondering if it is good exp solo.

That's like asking if LHC is good exp solo o.o
Anyway, when ever you have enough hp, you can.
I tried to train today on my db with 9k hp with decent HB and I died a total of 3 times in 45 minutes -.-

You can't enter until 165 and you'll need a lot of HP to train there as ^ said.
It wouldn't be efficient to train there solo, at all.

You can't enter until 165 and you'll need a lot of HP to train there as ^ said.
It wouldn't be efficient to train there solo, at all.

You can be doored at 160

Your party needs a crap-ton of DPM to even get good exp. Never train there unless you can get a party of 6 very capable people or 5 + HSer. And the archer knights, at least for me, are so annoying xP