The best is to start healing at low level dungeons, then you can adjust slowly. It gets more difficult later. For me, the easiests dungeon to heal are Tam-Tara or Copperbell Mines, so you could try those. Actually, a lot depends on party members (some constantly get in aoe or stand in poison >.<). If you really are afraid to go into dungeons first, try out guildhests. They are short and start at level 10 and first few are really easy to heal (and you get exp bonus for doing each first time with every class).