A lot depends on things like your age and whether it's the first time you have been caught.If you have been supplying your friends it will be taken very seiously.
You'll be arrested and have your drugs confiscated. You get taken to the police station for a formal warning. Your parent or guardian will be asked to come to. If it is not your first offence, or you have been supplying or dealing, you are more likely to be charged.
18 or over
If it is a less serious offence, an adult may not be arrested. They might just have their drugs confiscated and receive a warning. If an adult has been caught before or the police think they are dealing they are likely to be charged.
If you are found guilty
If you are found guilty of having the drugs for personal use, you may be fined or given community service. For things like dealing or supplying, you could be sent to prison or a young offenders institution.