Yay! Check them out - there's a million in one ways to do it so find whatever resonates with you and run with it! I started off small and worked at it little by little.
Don't get caught up in the quieting your mind to sit and "be" so much - its about noticing those thoughts and letting them float through..self correction is a huuuuuge part of it (that part is endless and will spill out into your day to day stuff) Catch yourself when you're spiraling down into a negative thought and tell yourself Stop it! I used to have to stop myself 100x a day .. 2 years later it's maybe 10x a day
I found it unbelievably helpful for my anxiety and depression too.
I like to focus on the sensations of breathing slow. It sounds nuts but I've deterred anxiety attacks as well as migraines with visualization breathing. Breathing in fresh, clean air and breathing out the pain.
Try guided meditations on youtube.. I still use those as a crutch when I'm especially distracted. sorry for the long response lol