how do you get to Kelethin from Qeynos and visaversa

[Kang]

is there a mariner bell or something and what level do you need to be?

[Deyaneyra]

From Qeynos either move out to Antonica, zone into Thundering Steppes and stay on the road to docks, should be safe there if you avoid the roaming aggro bears. On docks you can take the ship to Butcherblock Mountains and there make your way to Greater Faydark and Kelethin. Other possibilty: Buy a ticket in Qeynos Harbor (60s at Harbor Master near bells) and take the mariners bell which shows "Voyage by sea" that takes you directly to Thundering Steppes or Nektulos Forest docks, take ship there. Easiest way: Let a wizard port you there. Whenever you run by a druid ring harvest the blessed shrubbery there and next time also a druid can port you there, wizards don't need these.