I would cut the bread and salads. Bread just isn’t good even if it’s whole wheat. Salads don’t tend to have a lot of good nutritional value. Tuna is out of a can and packed with sodium. I would drop the cheerios too.

Increase your workouts to 5 days a week. Focus on heart rate rather than distance. Not sure what your health is or ability, but you should be able to find general ranges online as a guide. 30 mins a good time, but, again, 3 days a week isn’t enough. Your body weight exercises are good, but I would add weight and resistance training. The day after a good workout you want to have some soreness. There are lots of routines online, but, generally you want to isolate muscle groups or at least coordinate primary and secondary muscle groups such as back and biceps or chest and triceps.

As diet goes, simple is better. Stick to complex carbs like brown rice and quinoa. Eat a mixture or lean meats like chicken and tuna (not from a can) and healthy fatty meats like salmon. Snack with things like nuts. Replace butter with olive oil - rule of thumb with fats is that they should be liquid at room temp.

Drink plenty of water and get plenty of sleep.

They biggest thing is to stay consistent. Meal prepping helps a lot with this. Keep calorie intake appropriate too. You don’t want to have deficits that are too big.