Tampons are not recommended to pre-teens or teens.
Tampons can lead to Toxic Shock Syndrome (TSS) - the risks are higher in pre-teens and teens because your vagina is more delicate so more prone to tears that allow TSST-1 toxins responsible into your bloodstream, and you're less likely to have TSST-1 toxins. It's best to use pads to begin with, then if you want to use internal options opt for menstrual cups as they are safer and make periods easier.
If you have started menstruating, it is never too early to try tampons. It can be uncomfortable at first, but many females prefer tampons over pads once they get used to them. If you want to try them, read the box (there are helpful pictures), and don't get discouraged if it doesn't seem to work well right away. It takes some practice.