>>542096472
Why are you searching in English? Search for 트릭컬 or トリッカル and start following a bunch of artists until your feed is filled with Trickcal.
>>542096820
For the fastest immediate gains, gear. Also when you've got nothing better to do you'll be dumping it into gear for your unused characters as well for the global bonus from rank-ups.
>>542097014
There's Cheeky as well, most of the guilds fill up immediately or are private so it's hard to tell how many there are currently. I'm level 35 and close to starting my own guild, but I probably won't open it up to the public either.