The rest maximum is 30 bubbles of experience or 1.5 levels (240 hours of not playing the character, 10 days). If you intend to create a primary character, it can’t hurt to have a secondary. Log in to the secondary character every ten days; gain Tibia Gold a level and a half of experience, and hearth back to the inn.
If the level number is grey, green, yellow, or orange, you should be able to attack it with little problem. Grey enemies yield no experience, green ones give about 50-90% experience (depending on level), and all others give 100%.
If you tend to be a solo person, but don’t want to be, open up the social menu by hitting “O” and clicking the box that says, “I would like to join a group.”
The leader of a group (indicated with a little crown) can set the “looting type”. Items or “loot” can be distributed to members of the group in several ways: Artifacts have never been seen but are probably only dropped off raid encounters.
Instanced zones are full of elite monsters, so either be many levels above them, or bring friends. Instance zones tend to give the player the most experience, rewards, and money.