Just my little 2 cents. I dont recomend a tegu as a first lizard, but obviously if you do your research and are prepared (and have a lot of patience ), then you will have a blast. Just be prepared for anything if you get one.
I dealt with angry monitors before getting my first tegu, and i couldnt believe how mean and nasty it was. Ive also seen very nice tegus that are calm. Be prepared and ready for anything.