Only had one beet take this season

First season growing anything. Had a ton of sweet peas from a smaller bed, a dozen or so garlic bulbs that were tiny, then we got this behemoth beet! Planted about 20 seeds and this was the only one that grew. Probably should have picked earlier when it was smaller but was curious how it would go.

Soil is a mix of local topsoil and mushroom compost, but is still pretty dense. Any suggestions on making it a bit more workable?

Ignore the pile of weeds behind everything. This summer has been hell. Thankfully no weeds took in the beds!