About 10 years ago, I bought 500 bitcoins, of which I used only 10, meaning that 490 bitcoins remained.
Of course, I know what they are today
You oined the forum over 1 year ago, and obviously knew what bitcoins were since then, but you only now remembered that you had 500 bitcoins over 10 years ago, that seems a bit odd.
If you actually did have that amount of Bitcoin, you would need to know a bit of information to be able to recover your funds, otherwise it would be impossible to recover them.