I've always been a firm believer that you work on form at a blank bale, learn your arrow trajectory and sight picture on the 3D course, and learn about picking a spot and concentrating on that spot on the line shooting targets.
but this is what you should do for fun and practice all year preparing for hunting season...
i like the the tennis ball game, an the stuffed animal safari in the yard sounds like a hoot....but I'm a believer in getting your hunting set up dialed in and your quiver loaded at least 2-3 weeks before your season opens, and shoot only that bow with broadheads, and only 2-3 arrows a day.
i keep a 3D deer set up in the back corner of my shooting area. I stalk the deer from different angles each morning, and take one shot only...at noon, and in the evening i do it from a different angle at different yardage...... by this time of year you are either ready, or you are not, and it's the first shot that counts.
I've used life size deer targets on foam blocks too.... if you want to shoot more, go pull that arrow, and shoot again after stalking to a different angle.
i don't do a lot of tree stand hunting so i have no recommendations there. it all boils down to you are either ready, or you are not.
as far as encouraging teen age boys to go hunting.... i believe your success is going to depend on which way the wind is blowing.... a little perfume and a short skirt will trump elk urine and spotting critters in the woods every time..... good luck to you on that one bro...