WELCOME!!!
You want to get back into training your dogs more??
HA, HAVE YOU EVER FOUND THE RIGHT SPOT!!

GLAD YOU ARE HERE!!
Your dog is adorable, feel free to post more photos of the other dogs, too! I like your goals very very much!!
My dog and i have never had the "who is pack leader" talk, nope.

I don't much buy "pack leader" stuff
at all, nor do i buy everything i read. But, to each his own i guess.
I love that you are training dogs of all ages there!! YAY FOR YOU!!! Dogs of any age can learn tricks and cues!
Re: getting your dog to come when you call, that is sort of an ongoing thing, imo. Some tricks, you teach it, and dog has it forever.
But, for some dogs, "recall" has to be maintained, to be kept razor sharp. This is not what i think is a super easy thing for all dogs to master, but, it can be done! Sometimes, it seems this is easier for some dogs, than other dogs...this wasn't that hard for my dog to get idea, really.
Here are some threads on how to teach your dog to come when called:
http://www.dogtrickacademy.com/members/forums/threads/recall-help-please.4055/#post-28963
everyone has their own way to teach recall, post #4 in this thread, is how i did it:
http://www.dogtrickacademy.com/members/forums/threads/recall.4659/#post-37170
this thread has some good ideas on games to play to strengthen the dog returning to you:
http://www.dogtrickacademy.com/members/forums/threads/retrieving-game.4525/#post-34826
and more recall game ideas here:
http://www.dogtrickacademy.com/members/forums/threads/fun-recall-games.3394/
GOOD LUCK, AND post any questions you have!!