one...can you summon her or do you have to go get her and let her follow you to where you are ?
two....how do you get her to use or wear the weapons or armor you " trade " with her ?

You don't summon her exactly, whenever you fast travel or enter a new area (like a cave or something) she automatically appears by your side. As for equiping stuff, talk with her, select the "hey can you carry my stuff" option, put things from your inventory to hers, then press the equip button and she should equip it

She will only equip things that are better than her basic gear.

First of all, you're not asking because you brought her into Shalidor's Maze, are you? If you go to Shalidor's Maze, there is a rather annoying glitch that makes your follower stay in there. I'm not certain if it's patched away, but best to play with caution.

Otherwise, followers tend to appear right beside you after you wait, sleep, enter a new area, or fast travel. If you're just walking or running along, they might sometimes follow you from quite a distance. Sometimes, if you're navigating topography that's difficult and rugged, the follower may likely walk the safe path and longer path to get to where you're going... in which case, if it's too long a path, the follower may just materialize out of nowhere instead.

Follows also use the best available equipment in their inventory according to where they're skilled in. Lydia, would more likely choose steel plate armor... but Jenassa, more of a stealth character, would choose leather or scale armor.

no...sometimes she gets in the way so i send her home...only to need her help later when i'm on a quest and she's on the sofa at home eat'n bonbons...i was just wondering if there was a way to get her to come to me rather then me going after her
second question....so she basically picks what she likes...lol