Adding an outlet off a basement light

Hi everyone! We have a mostly unfinished basement (insulated, plumbed for a bathroom) that we're going to eventually finish (within 2-3 years). Until then we'd like to put some exercise equipment down there and the only outlets (by fuse box and by sump pump) aren't particularly convenient.

There's a series of pull-string lights that share a double fuse with the furnace and I was thinking of running a single outlet off one of these light boxes. [Here's an image of what I'm thinking](https://imgur.com/a/1kpZWME).

While I've worked with electrical some in the past (mostly replacing outlets/switches) and am confident about being safe (fuses, non-contact voltage tester, etc.) I've never actually run a new outlet before. However, it seems pretty straight-forward I think?

I was planning on getting a roll of Romex (probably 14/2 but I still have to check), maybe some type of flexible conduit (not sure if it's totally necessary but with kids running around maybe?) and then a box and outlet. Am I missing anything obvious? Any suggestions/comments?