Alright I'm going to give some serious advice as someone with some experience. Start real small if you don't have experience, takes a while to get used to it. I would suggest anyone considering experimenting to start with just a finger (cut your god-damned nails short and file them down a bit, hurts like a bitch if ya don't) and LUBE, you literally can never have too much lube. (if ya happen to have been born with a dick, you should try to find the prostate. Should be just a couple inches deep, kinds feels like a bean, play with it a bit, should feel pretty good.) If after a while if one isn't too uncomfortable try a second one but don't force it, if it starts to hurt just stick with one. Practice is the name of the game, all it takes is a bit of patience.
Now after you start to feel well and stretched out if you have a toy now might be a good idea to try it, again if it hurts stop. You don't want cause any damage. I wouldn't recommend any toy over 6" to start, look for something around 1-3 inches in diameter. I would actually recommend getting a training butt plug set like:
https://www.amazon.com/Plugs-Trainer-Silicone-Beginners-Starter/dp/B07YHMQQQW
Once you get used to larger sizes, toys become a lot easier to do
I don't really make full music, but I record bass. Here's the best track I've done using pre-made tracks.
https://www.bandlab.com/the_clicky_bassist/industrial-hatred-eeb60a08
If any guitarists or drummers wanna do a collab - hit me up
This is a boss battle theme for a game that I want to make.