Recently, the teacher asked me to do a pcr amplification, which is the first time for me. I really don't understand. Then run the glue, the teacher can't read the picture.

This is a failure. The leftmost band is the mark, which is used to run glue. The farther away from the hole, the smaller the molecular weight. How many base pairs each band represents depends on the tag you use. From this picture, you didn't come out because the molecular weight is very small, that is, primer dimer, that is, primer. See if the conditions are wrong or you forgot to add something.