Need someone to put on fertilizer
 

I have a lawn mower, but he does not do fertilizer. Every company I have called either does only mowing or full service. I have the fertilizer but no spreader and I ruined a lawn once because I am not good with spreaders! Does anyone know anyone who has a spreader and will do this?

I have recently talked to master gardener, and the lawns here can be finicky about fertilization. You may want to double check whatever you bought and make sure it is the correct one for your grass, and also how often and how much to put down. Do not fertilize during the winter.
Master Gardener, Pinellas Library 9a to 3p Fridays.

fertilizer spreading
 

Reason your mower person will not apply lawn chemicals is that they need to have a license to do it.
You mention you have burned your lawn in the past. Reason could be that you applied too much, applied it too heavy in one spot or applied the wrong product at the wrong time on the grass type you have. BEFORE YOU PUT SOMETHING DOWN, you need to know what type of grass you have and proper care for THAT TYPE of grass. In the older parts of the villages (north) most people have St Augustine the newer parts (south) are most likely Empire Zoyzia. You need to measure-calculate how much grass you have so you know how much product to apply. You will be able to find what to apply AND WHEN, for either type-THEY ARE NOT THE SAME. The cooperative extension is very helpful with stuff like grass identification, weed identification, fungus identification, insect identification, soil testing etc etc.

My lawn is 4800 sq feet call it 5,000. I use a Scotts hand spreader. Green plastic thing you will see a most every garden supply place. You want to get the one with a loop to fit behind your arm. Fertilizer is heavy and the loop makes it much easier to support that weight. The cost is like $12.00 and a big plus is it will store on your shelf so takes up very little room.

I would read up on what fertilizer to use and check with a local store or two. Then do it yourself.
Maybe put it on at 50% of the rate.
Try On Top of the World News Ocala This is a community newspaper but each month they have info on lawns. Once a year they cover fertilizer. Maybe the March or April issue.