Depends on if you used a lotion or not. Most lotions have DHS in it, which is like a tinted moisturizer. If you used a lotion you should wait 4 hours so the DHS has had time to completely soak into...
Generally it is always best to shower before you tan. First of all this increases oxygenation of the skin and it takes UVA + UVB + oxygen to tan. Second, lotion absorbs better just after you shower....
Tanning beds have a "max" time. Work up to the max time minute by minute and do not tan longer than the max time. tanning beds are usually 10,15,or 20 minutes. The less max time the bed has the...