How do i track my calorie intake, only eating home made food.

Current body condition is-

Height - 5'11

Weight - 108 kg

Recently started to workout after 1 year. It's been 1 week at the gym + increased water intake + no or very less eating after 6 pm. I try to skip dinner or eat very less and workout 6 days a week. My weight was 95 kg last year around june july till then i gained 13 kg in a year because i left gym no walking basically no physical activity for 1 year only eat sleep repeat. But now i have started again and am hoping to go around 80-85 kg in a year with lean muscle mass.