The level is a strength rating. A higher level means stronger lamps and a shorter session for the same result — a Level 5 bed does in minutes what a low-level bed takes most of half an hour to do. That is the appeal, and it is also why the single most common mistake is treating the first visit like the tenth.
The timer is self-serve, so the length is yours to set — keep your first few sessions well short of the maximum. Bring lotion — the beds work considerably better with it and considerably worse without, and dry skin is most of why a first session disappoints people.
Not after colour at all? The lay-down also runs a red light mode, included the same way — red light therapy in Port Huron.