How to heat up my leopard geckos cage?

The warm side needs to be 85-95 degrees during the day and 75-80 at night. The reason why your gecko doesnt come out is because they are nocturnal. They come out when the light gets turned off, the light mocks the sun and she thinks its daytime so she she sleeps and when you turn off the light she thinks its night time so she comes out. You can use a 50 watt daylight bulb, it works great I have one and it keeps the basking spot in the low 90's during the day (I have a 10 gallon) but because you have a 30 gallon you can also keep the UTH on 24/7 to produce more heat because of your tank size on the basking side, also make sure you have a thermometer. I recommend a digital thermometer which is like $12 for a cheap one to make sure the basking side isnt to hot because standard ones arent really accurate like a digital.