Hey needing advice

I need help i have just started lifting weighs to gain muscle and lose my belly fat is there any1 doing this and whats the best way to go about it. My diet is for breakfast oats and a apple plus a protein shake dinner anything from chicken pasta to a chicken salad and tea chicken breats rice and broccoli. I feel that my work out isnt going good as i cant lift heavy and not sure what exercise is the best as i see many exercises been done in the gym. Any advice would be much appreciated thank you.