I think the reader can really see your love of Tennis and your determination for something you really love.

-immature moment, don't mind this-
Tee-hee, what's a hard job? One day I'll learn the Tennis vocabulary, one day! -holds fist in the air-

But really, it was a quaint poem. My only critique is that it seems as though you made it shorter than its full glory. But that's only my I-love-long-poems opinion.

Overall it was very satisfying poem. I really want to learn Tennis now XD