In order to keep your studying in secret, try keeping everything in your head, not writing huge books like Necronomicon or Grimoire of Ancient Worm with bright covers and pentacles drawn on them) That will certainly be noticed. You may make some amulets, yet hide them well. Also, avoid talking about your interests. Some people might then use this info against you or just start bullying.
And about the issue if you are able to perform magic or not, just try asking other questions first - can you dream of some things which are far from our terrestrial life, this mediocre existence? If you do, then you have the fantasy. And if you have a fantasy, then you have the greatest source of energy for your magic and magic itself.
There are no institutions anywhere where you can get some exam on your magic abilities or whatever) Just if you have interest in mystical things, folklore, or just horror fiction, then magic would be a nice hobby for you. And if you spend some time on it, you might even move your interest on a higher level and become a master of your subconsciousness and magic... It needs time. If you like it - it is yours, if you don't - it is not.
If one likes being a shephard, he won't be able to blacksmith. Yet, if he is a shephard who would like to try himself as a blacksmith, it is likely that he may succeed there.
Hi, I'm quite a newbie myself, but from what I read basically insuccess in spellcasting is due to little belief. "But how I can believe in something I haven't seen in action yet?" I don't know and it bugs me just as much as it may bug you. That's why I'm on this Quest for Knowledge of mine. Oh, and for the fun of it!
* These are just my personal opinions/ answers, someone else may have different ones*
First off, everyone is able to perform spells and rituals only if they real! Spells and rituals to shapeshift, flying, teleporting, etc... Those spells are fluff which is considered fake. I can link some links to spell casting and everything you need to know about it.
Secondly, just find someone books and websitessuch as these to learn more information and spells don't bother to find books if your parents might find them and throw them away it's a waste of money. ( I am assuming, you're underage since you wanna practice in secret, just assuming). Now, you do NOT need any tools or anything fancy or special to do magic all you really need it yourself! Some may arguesaying tools and other needs make a spell stronger.