Thanks for the query.
Secretion of precum when you are aroused is completely normal thing.Precum is secreted as a lubricant to prevent friction during intercourse and it is secreted before actual semen secretion.So this should not cause any health concerns.
Again wet dreams are not to be worried about.These are common among teens and don't need medical attention or any treatment.Masturbation
is not unhealthy thing.Such concerns are common at your age, you just need to go with your body changes.
Please relax and don't worry about these issues.It would be ideal to find a good source of sexual education, good books can be particularly helpful.
Hope this answers your question.Please ask if there are doubts.