Sveva does have some great lighting sets. HDRis give you a lot of options, too – I personally like Paper Tiger's sets and use them often: https://www.renderosity.com/mod/bcs/vendor/PaperTiger?username=PaperTiger&category=3D+Lighting+%3A+Cameras

You might also want to look up the three point lighting system. There are some great (free) tutorials out there which use the standard lights built into Daz. These were a huge help to me when I was first getting started.

Best of luck, and please let us know if you need more help!