I went to the gym earlier today as i am trying to be a little healthier than i have been recently! It was actually really fun, i went on my own and just focused really. It was nicer because the gym was practically empty so i didn't feel self conscious. It also means that now i'll get a good nights sleep because i'm so tired from it! Even if you're not looking to lose weight or tone up or any reason like that, doing exercise releases a chemical called endorphin's inside of you. Which make you feel better and give you energy!
Another tip on staying healthy is that, if you buy junk, you'll eat junk. But if you try and when you go shopping or tell whoever does the shopping for your household that you want them to just buy things good for you, then you have no choice but to eat well because there's nothing unhealthy to eat in the house!
Also, go shopping when you're full, or have just eaten. If you go when you're starving or craving something then all the food looks appealing and you're more likely to buy junk! If you go when you're full then you don't really feel like eating junk so you won't buy it. Honestly try it! it really helps.