Calculate your TDEE (Total Daily Energy Expenditure), start tracking calories and try to aim like 250-500 above your TDEE.
If you're trying to bulk up instead of just getting fat, you obviously need to pair this with some sort of workout routine. I'd recommend Starting Strength or any similar Full body x 3 day routine.
I had no appetite to eat 5 meals a day when I started either but you'll basically just need to get over that if you ever want to progress. Liquid meals are a great way to start.