How to prepare for garden turf

Iam now ready to start and lay a new lawn/turf in my back garden but I don't really know what to do next.I have weed killed the full garden so it's pretty much dead but what else do I need to do before I lay new turf? Iam aware my garden is a bit uneven also so what would be best for levelling it all out a rotavator or is there a cheaper option available to me?

thanks for any help