What could a lump in the tongue. Its inside the tongue. And its hard and small. I'm 16.And the only thing I can think of is cancer. I'm so scared. No tabacco?

Biopsy. I would recommend having the lump biopsied by an oral surgeon. Then you will know for sure what it is after it is reviewed after its histology is reviewed under a microscope.
See your dentist. Your dentist or oral surgeon will be best to evaluate this for you. Your peace of mind will be worth it.
Lots of things. Most of which are benign. Oral cancer in a 16 Y.O. Who does not use tobacco is extremely rare. It could be cyst or even thyroid tissue. I'd see an ent. Depending on your exam, the ENT may order a ct or mri.
Need more info. It could be nothing serious or it could be serious. Please get it checked by a dentist or doctor. It is probably from trauma like biting your tongue or some other injury, but it could also be serious.