Tongue block all the time?

Hello David,

I just started your LOA. I used to play a little bit of harmonica but I really wanted to learn tongue blocking so I can learn Quiet World some time.
My question is, should I play with tongue blocking all the time? I'm still in level 1. I'm asking this because I'm thinking of trying to play the songs that I already know with tong blocking but I don't know if this will help.

Thanks,

Vitor.