I understand what your are stating. Since you have studied and now are ready to begin to start casting. The next step is to begin. Just do it. You may as well start now as any other time. Where to begin? Always prepare before you begin. Try to organize what to do at least a week ahead by the Moon phases, waxing, full, waning etc. Day of the week, time of day. Organize your thoughts, write down the steps you are to perform, step by step, and practice in your mind, days before you begin. And do not tell anyone of what you are to do. Cynicism from others kind of gets to you.
1) Review the spell you have chosen, to at least familiarize yourself when you read it out loud in your 1st cast circle, if you haven't had time to memorize it.
2) Choose some background music if you want to. You can play Celtic music in the background, I personally played "Calling All Angels" by Train. Later on, when I was casting a strong spell that I needed as much emotional energy as I could muster up, I played "Magic Carpet Ride" by Steppenwolf. Play whatever gets you in the mood for your spell work.
3) Have a list of all the correspondences that symbolize the cardinal points of your cast circle and your spells(to include the type of candle color for your spells).
4)If, it is your 1st casting, have all your symbolic tools or, none at all. You have a choice; East/air - Feather, incense, wand, yellow candle, South - fire(red candle burning), matchstick, athame, West/Water, seashell, water cup, blue candle, North/earth - small clay or stone bowl with salt(later on get sea salt if you can), pentagram (a disk with the pentagram on it, mine is a palm sized wooden thin disk, inlaid with a brass pentagram design in it), green candle. You can have your deities in the middle or, a yin-yang symbol and research what else here in the middle.
5)If it is your 1st time and, you do have your symbolic tools, then come up with a consecration rite to bless your tools.
6) I cannot presume to suggest what type of spell to cast as this is very personal and I am a student of the Magickal Arts as you. However, my very 1st spell, after casting my 1st circle, with just the yellow candle and a feather, a red candle and a match-stick, a blue candle and a small clay cup with water, a green candle and a small dish with salt on it. A white candle in the middle to represent spirit.
I cast a protection spell to start my magickal path. It's all up to you. Do what you feel.
Hope this helps. Blessed Be.