Here is your witchy tip of the day!
If you're practicing in secret, there are multiple ways to hide the fact that you're a witch. The first would be to disguise your alter by making it super aesthetic. Then you can just tell your parents that it's there cause it's pretty. A pentagram? No, that's just a star my friend made for me. Candles? They smell nice. Crystals? They're decorative. Moon water? The water in the mason jar looks pretty. Small statues of deities? They fit the aesthetic. Flowers? Totally not offerings... they just look so pretty. You get the gist.
I find that a lot of witches, including myself, have witchy books about witchcraft... such as spell books and calendars and stuff as well as a Book of Shadows or a Grimoire. I have a super helpful tip for hiding those. Go to a book store, preferably Half Price Books (some of the books there are only a few dollars... I've found some for 50 cents there before), and buy a large book. Then cut a hole in the central most pages large enough to fit your witchy books. Place them into the hole and close the book up. From the outside it will look like just an ordinary book. It's good to disguise this book in your bookshelf, though, so nosy siblings wont pick it up and try to do stuff with it.
I myself, as a secret practitioner of witchcraft, use these disguises, and my parents haven't found out.
Remember, stay safe and keep crafting! Blessed be!