Well done for getting back into it.
If you’re starting off at home, focus on bodyweight stuff - jump squats, press ups, pull ups, burpees, squat thrusts, mountain climbers, dips, sprints, planks etc. And consider getting yourself a kettlebell - really versatile piece of kit, and fairly cheap too. If money really is an issue, buy a sandbag from a DIY shop, and do some presses, rows, squats etc. with that.
As for food, stick to things like - whole eggs, meat, fish, cottage cheese, whole milk, fruit, veg, oats, nuts etc. and just adjuct quantities depending on whether you want to bulk or cut.

Hope this helps.