noun
gofer
GOH-fer/ˈɡəʊfər/
A low-ranking assistant who runs errands.
The gofer delivers coffee and mail to the office.

Etymology
The phrase “go for,” as in going for coffee or spare parts, became a name for someone sent on errands. It turns a routine instruction into a label for the worker who carries it out.
In context
you become what's known as a "hang-around"-- basically a gofer.
More examples
- The gofer collected lunch orders for the crew.
- She resented being treated as a gofer rather than an assistant.
- The manager sent the gofer to pick up the documents.
Forms
gofer · gofers