Let me think here. It must have been grade six or so, so I was about 12. Our teacher took us to the public high school in town to see a production of The Taming of the Shrew. I was enthralled, but other than reading Romeo and Juliet it lapsed for me until high school where we studied Romeo and Juliet, MacBeth and Much Ado About Nothing. The latter is what got me into Brannagh, I love how Beatrice and Benedict snipe at each other.
First play would be Jacob Two Two and the Dinosaur (based on the book of course and seen at about age six) and last play… Hmm. It’s been awhile, I forget the last one I saw, I like going to the children’s festival plays. I think the last play I saw was about a rock. Just a rock and the world as it passed it by. Really nice actually, though now I wish I remembered the name of it.
A Midsummer Night’s Dream when I was probably 8 or 9. We were living in Michigan at the time, but we went to visit relatives in Canada and got tickets to the Stratford Festival’s production.
I also saw **A Midsummer Night’s Dream **, as a field trip in high school. We were bussed into LA for it. We were up far enough that the opera glasses that one kid brought were very popular and got passed around the whole play.
The first plays I ever saw were between first and third grade: two were fairytales (I want to say sleeping beauty and Goldilocks) and the other about Harriet Tubman. As for Shakespeare, we saw a production of Romeo and Juliet in 9th grade and Twelfth Night in 11th.
My most fun Shakespeare experience, though, was during college: as part of my Shakespeare class we had to do a production of any of the bard’s works, and in any style. We put on A Midsummer Night’s Dream as a Jerry Springeresque talk show. I was the host 
I wish someone had taped it because not only did we get an A, it was fantastic fun too.