When wiping after bm the toilet paper has black specks as well as the normal stuff. bms are solid, no visible blood, but by about the 3rd wipe there is a little blood on the paper, but might be from aggressive wiping. could this be something serious?

Dietary/medication?: Difficult to say what the black specks would be, but if you have been eating differently (especially anything with small seeds in it) or a new medication that could possibly cause it. Aggressive wiping could definitely cause small amounts of blood. At your young age the risk of something serious should be low, but if the changes persist & you have no recent diet/medication change a Dr visit best

Aggressive wiping: It doesn't seem that there is anything wrong at this time. Aggressive wiping can cause irritation and some bleeding. In stead of wiping multiple times with a dry tissue, try dampening the tissue and then wipe. As always, if you seem to have any further blood then an examination is required, but this seems doubtful.