How would Utopia even work?

So I read Utopia by Sir Thomas More recently for school, and it got me thinking about this ideal world More wrote about.
As regards to employment, everyone would learn a trade or two and choose which one to ply, depending on which they liked better or what the economy called for.
It seems that the slaves in Utopia were the ones doing dirty work.
But how could it be a Utopia when there’s hardly any freedom of choice?
You choose from a few trades which ones you’d most like to do. What if one wanted to become a teacher? (That was never addressed in the book.)
Houses would all be the same; cities would all be mostly uniform.
What exactly is Utopia? Is it a place where everything is equal? A place where everyone is happy, getting what they want? Is it possible to have both? The people in Utopia were apparently happy, their employment was fulfilling, and they were all equal. But I wonder if this perceived happiness was contentment rather than pure happiness.

What are your thoughts on Utopia and on how “utopic” it really is?