Is tai chi easy to practice?

The movements are not physically strenuous and will not strain or tax the body.

However, easy or difficult are relative to the individual.
It depends on memory, coordination, patience and how committed you are.
Also, there is the question of how fit you are to begin with.

You cannot reasonably hope to master tai chi overnight.
The art is very in-depth, with many levels of skill and achievement.
There is always more to uncover...