How do you start a coven in your area where you live? How do you manage it? How do you promote a person in your actual life coven to be the high priest of priestess?
So unless you know enough about the religion and enough about what you want to be teaching and doing, then I suggest you shouldn't start a real life coven, and plus if you are under the age 18+, you becareful, not a lot of people would join a coven that has a 13 year old as Priest, they would like someone more experienced.
But if you wish to start your own coven in your town http://www.witchvox.com is the way to go.
Sutre13. You may very well have some experience; but not enough! You are still developing.Yes, I know that you say you "think like an adult".But all children think that! When I was 13 I knew everything! Now, at 81, I hardly know anything!
If your only 13 and you have been studying for only 5 years, your for one underaged, and for two still a newbie. I'm not trying to sound rude but no one will gain so much knowledge in 7 years and be able to start a coven. For now continue till your 15 and then maybe jion a coven. At age 18-21 you may create one, however you need all 3 degrees, at least more than 3 years of experience. Remember wicca is a constant learning path and no one will have so much studies to claim there knowledge. Wicca even at age 50 you will still be a begginner/middle and you still will never gain the knowledge. Only the gods can have the knowledgable rep.
Wicca tends to be the biggest group that uses the title coven for their group. Others, like Heathenry, have kindreds. Kemetic Orthodoxy doesn't have special titles for their groups, because we're all one big community.
However you should be quite a bit older before you'll be able to make a successful coven/group, as you not only need the knowledge, wisdom, and experience, but you also need to be able to set up initiatory rites (of sorts) for each of the "levels" you intend to have in your group. Otherwise it's fairly...limited to simply state "Joe-witch is now the High Priest." There has to be some sort of process in moving from a standard member to someone to look up. A test/ordeal of sorts.
Most genuine groups will usually only take on a member who is 18 years old (or whatever your consenting adult age is for the country) and even then, any group worth their salt will assess you for your dedication and maturity.
I know some schools and universities have groups and societies for studying together and group ritual, but personally I never wanted to be a part of them.
You can study and practice your path on your own. Many groups will meet for the holidays they recognise and for social outings etc. maybe some group rituals now and then, but for the most part your path, is your path, and you have to walk it.