How do I buy something off the internet without my parents?

I would advise that bạn don't do that.
Respect your parents.

I simply wouldn't. They'd probably get mad if they found out. Save yourself the trouble and just ask them; if anything bạn can ask them to get it for bạn but wait until your birthday hoặc something to give it to you.

Why won't they let bạn get it?

If it's something they legitimately don't think bạn should have, then bạn should respect that.

If they're being mean, then just figure out another way to get whatever it bạn want so badly.

Even if it were in secret, your parents are bound to find out somehow. They always do. They will know you're hiding something. Most online stores, want the costomers to have credit, and if bạn are under 18 hoặc 16, they will want your parents hoặc gardians permission. And if your parents won't let bạn get it, may not sound fair but it could be for a good reason. I don't know what else to tell you.

Sorry but bạn should really obey your parents on it. What I normally do if I want something online though is offer to buy it myself. I got fifty shades of grey, darker, and freed that way. I just paid my parents how much I was going to pay on their card. I had permission every time I do this. Maybe if bạn bought it yourself they'd change their mind, but that depends on what you're buying

Maybe get a friend to buy it for bạn and bạn pay them back?

Honestly, I have no freakin idea :/

Well first off, if it's Beats earbuds bạn want, and bạn have your own money; can't bạn just go to the store and buy them? It's a really được ưa chuộng brand every electronics store sells them.

Secondly, hypothetically speaking, bạn could steal their credit card and try to enter the information yourself. However your chances of getting caught are about 110% because your parents will either
A. catch bạn with their card
B. notice the charge on their credit card bill, hủy bỏ it, and never let bạn get anything online ever again
C. Notice bạn with the headphones and make bạn return them.

Long story short, look for them in stores and buy them with your own money if bạn have it, otherwise just wait, maybe bạn can try getting them as an early Birthday present hoặc something?