the lawn in our rental house and learning how to take care of a small lawn. It's not that difficult, nor that expensive, but I'm learning and it's frustrating at times.

I apply fertilizer in early spring/late fall (if I remember). T

weed and feed in may (although as noted above I might start doing it sooner and once a month).
I'm adding an insecticide once a month this year as I have ant problems and I suspect grubs as well.
I also add seed once a month (especially this year since I've had alot of lawn damage from what I suspect are insects)

The hardest part for me doing the lawn is the fact that I have a decent sized yard and use a 12" corded lawnmower that I bought for $6 when we got into our rental in 2017. Kids think it's funny to unplug the mower haha. Darn thing won't die, although I hope it lasts 1 more year because I expect we will be moving in 2023 and will probably buy a good gas mower then.