Jem, lawns are labour intensive and there are no easy ways once it is neglected. Treat it as an ongoing project and you are right to get the moss off first. Now it will need spiking, depending on the size you can hire a machine that will take plugs out of your lawn or go over it with a good heavy garden fork. Press the fork tines into the lawn about six inches apart and move up and down the lawn in straight lines so you do not lose track. Have some washed sand handy and throw shovel fulls on spreading it as you throw it on then with a stiff brush sweep the sand into the spikes holes. That allows water in to the roots and air. Any bald patches you can buy repair kits in any Garden Centre which consist of seed mixed with compost or sand, you could just buy the lawn seed and mix your own. Fork over the bald patch lightly then spread the seed and compost evenly sow enough to repair the lawn and some the birds will take, to stop them put some mesh down over the patch or stretch cotton across some spikes round the patch. Let the new grass get a good hold before the first cut even if it means mowing round the patches. After care is a good feed and weed, they are all about the same twice from spring about six to eight weeks apart and water it in if dry. In Autumn after the last cut use Winter weed and feed and leave until the grass starts to grow again in spring. Then do it all again.
Hope this helps Frank.