A general purpose lawn weed and feed (and with a moss killer if needed) would be good but don't apply it 3 days just before mowing the lawn, then don't cut the lawn for 3 days afterwards. Also don't compost the mowings for at least three cuts after so as not to contaminate the compost bin stuff. To apply it, use gloves and do it by hand or get a lawn feed spreader, depending on the size of your lawn. Scarifying is an autumn job.
