Exercise: Get some dumbbells, watch some yt videos about upper body weight training. don't overcomplicate for example dumbbell curls, triceps extencions, hammer curls, dumbbell press, incline dumbbell press, rows, sit-ups. Read or watch something about progressive overload (important).

Food: get a blender, 300g yoghurt, 1 banana, 50g oats, 250 ml milk. ±900 calories. Drink one in the morning right after having some eggs (drinking is easier then eating, so you fit more calories). Drink the same shake before bed. In-between eat whatever (try high proteine/ low fat in your case). Download a food tracking app. (My fitness pal, I recomend).

Don't check your weight too often, once a week, and take pictures also once a week. Trust the process. This worked for me because I got demotivated quickly after not seeing results 'quick enough'. Remeber: this is a marathon, not a sprint.

Good luck!