Should I become a member of PAA psychologists association of Alberta?

No.

Membership Fees:
Membership runs from April 1st to March 31st. After May 1st, pro-rated fees are available for new members. Contact the PAA office for details.

Annual Fees:
Full Member $310.00
Out of Province Member $190.00
Provisional Member $95.00
Student Member $40.00
Professional Affiliate Member $190.00
Psychological Assistant Member $190.00

What’s in it for you?

It kinda sounds like you have to be, you know, an actual psychologist to join, or be endorsed by one.

Membership Benefits and Services

Sure!
Why not?

You should be studying or practising psychology for it I guess.

According to the @Espiritus_Corvus link, the only benefits are for people who are psychologists. First apply to a university and get a degree.