Hello! and welcome back.
I encourage you to browse through the stickied "Ragnarok Linkshells" thread atop this forum. Check out the websites and see if you can narrow down which ones you think are a good fit for you.
Three that I recommend checking out are
- Axiom, my own LS, a medium/small shell (about 25 members) with a balanced array of newer folks and longtime/ L75 players. axiom-online.org
- Triumviate, a larger shell with more mid-level and newer players, but with several endgamers helping out too.
- Musketeers, a larger shell perhaps weighted to the veteran side but with many newer players too.