There are very few lowrates at the moment, and most of them are extremely restricted with dualboxes, either no box or only 1. There's practically nothing to do as a solo player except play these shitty 2 week midrates or play l2reborn and look for party all day instead of actually playing.

You could try l2 firebird , friendly , casual , long term. X1
Low population , but you can easily find small parties even at lower lvls

like I said, both 1+1 box limit and low population, there is practically nothing to do except go slowly kill 1x mobs

L2Etina is opening again on January. It will be huge. Check the forum. https://l2etina.com/forum/