As far as getting outside for exercise - sometimes it's hard... We have a wii game, and if it's an "indoor day" due to rain, cold, snow etc... we play Wii Sports or Just Dance to get some excercise... but Wii can be expensive. So, there's a game called Hullabalo that gets the whole family up and moving... don't need to much space - just an area on the floor. Sometimes I give my kids indoor "obstacle courses" too... Even if it involves 5 jumping jacks, 3 hopping up and down off the couch, army crawl across the floor and then marching back to the finish line, etc...
As far as telling him... My son was 5, so he knew from the start - and now at 8, when people ask him about it, he says "I have diabetes, so I need insulin." and that's it. Most kids don't ask after that, but I always tell their parents they can ask me any questions... Here's an idea... My neighbor's daughter was adopted. She's only 7, so she really can't understand completly, but they've used the word adoption, and always go to adoption events and gatherings... They've always been quite open about it. So, maybe if you start using the word "diabetes" "blood sugar" "insulin" etc... with him, he will come to use them himself... Immerse him in the language just as my neighbor did with their daughter's adoption. Let him be able to answer the questions - for example, when he's asked, "Why do you have to take shots?" Let him be able to say, "Because I need insulin." or "Because I have diabetes." The kids won't really understand - but it usually stops the questions...
Finally, attend events!!! They are usually on weekends. My son, Jimmy, is the only T1D in his school district, so he has no "buddies" who can relate - for this, the events help!! Also, there are camps for diabetics, and Jimmy attended this past summer - which is when he began taking ownership of his diabetes. The cable guy came over recently to fix a problem we were having, and he noticed the "tester" on the counter. He said, "So, who has diabetes?" He said, "I do. Why, do you have diabetes, too?" And they had a whole conversation about how they care for themselves - Jimmy wanted to know why on earth he wasn't using the pump yet (the pump changed our lives!!!) And they even talked about the camp they both attended here in NJ!!! The camp and the events are so good - almost like "safety in numbers" where Jimmy is just Jimmy and the diabetes is completely normal and ordinary...
One last thing - definitely talk to your doc about carb counting... That's how we started out - and I couldn't imagine limiting him... He's a bottomless pit and a grazer, so between carb counting and the pump, the diabetes is more manageable. The Medtronic company is amazing - they do in home sales and training. I can reach out to my rep (who is AMAZING) to see if he has a connection in TX (that's where you are, right?)
God Bless, and give your babies a kiss and hug from Jimmy!!
Peace,
June