Hello! good to see you (sorta) anyways, before joining a coven, i suggest you have some spell experience. it is much easier and more helpful for your self to find the "magickal journey" we all go through on your own. afterall, it is YOUR journey. why are you so nervous about spell casting? dont worry about messing up and getting bit in the butt. sure, it hurts a lil, but it is only temporary. and the best way to learn is from your mistakes.
when i started casting spells, i learned as i went. i had this freind at school (not really a friend but a tyrannical girl who oddly enough liked me... as in loved. i didnt do it btw) who practiced as i did. so we decided to celebrate... idk mabon or something. it was the spring sabbat thing. i forgot the name. anyways, my point is, we both had prior experience with spells before meeting eachother, making it 100% easier to get stuff done.
a simple first spell to cast is an empowering spell, or something along the lines of opeing your third eye. something to really get your juices and energies flowing. then you can start with either love, money, luck, protection (recommended), and blessings. casting a circle isnt really as important as most think. it is only useful when calling upon celestial energies, summoning spirits, etc. all of which, are not that fun and somewhat complicated.
do not be afraid to jump in. you may have your head under a lil at first, but, in no time, you will be rocking the energies in your life.
ps. if you are EVER going to summon a spirit/entity. dont EVER summon a demon. they are extremely hard to get rid of and they are NASTY!!! in mind, looks, mouth, everything! so just stick to the manipulation.
pss. you dont need a coven to be powerful. sure, more than one person helps, but it is not always needed. most spells can be cast on your own time.
psss. before casting spells, learn to meditate. take like a week or a few days to work on energy flow. and make sure to pay your respects to the god and goddess. BEWARE OF 3 FOLD!