most important is the soil you are planning to turf. If you prep it right, you should have a real easy time of it. You can just dig over existing stuff, but try to remove any nasties like danylions or docks. Dig to a depth of a spit (ie a spades depth) and then stick in as much sharp sand as you can, ideally looking for approx 50/50 with the soil you dug over. Remove bigger stones, ones bigger than 3". Once you have dug over and mixed in, tread the soil down, rake then tread again. Rake to roughly level. Lay turf, loads of vids on how to do it. Use a sprinkler twice a day for about 30 mins each time, make sure turf is completely wet. Don't walk on it for about 6-8 weeks, if you lay the paving when you turf, you won't have to walk on it! First cut (after 6-8 weeks!), take the top 1/3rd to half off and leave for a few days, then take another third a few days later. after a few months give the lawn a feed with lawn fertiliser also if dog wees on lawn, immediately chuck a whole watering can of water on the area. If you follow this, you should have a lovely lawn with very little maintenance and if there's no shade, very little moss. The sharp sand sounds excessive, at 50% but trust me, grass loves free draining soil and will grow like a champ.