The bigger blobs seem to be air bubbles, the scratches seem to be done by a squeege, and the crude at the bottom seems poorly diluted developer or sand in the water. Plus it looks like you have scanned everything through your shirt.
To Sum up:
Make sure, the developer and water is clean, best to use demineralized water for this step, and if unsure, filter the developer through a coffee filter.
Dislodge the bubbles at the beginning and after each agitation by banging the tank 3 times against a hard surface.
Avoid using any kind of stop or water bath in the middle.
After washing, use last rinse bath in demineralized water with a drop of wetting agent, then hang to dry without squeeging with anything - pull the film away from vertical for a minute after hanging, it will help the fluid flow away along the borders.
I am not sure 4 minutes is enough for fixing - put a piece of cut off film leader in your fixer solution, and see how long it will take for it to become completely clear. You should fix twice as long.
Put your shirt away when scanning.