Why did most states want to change the articles of confederation

Correct

Concurrent powers are powers where both the federal and state government will have involvement.

Concurrent powers include things that both the federal government and state governments do in their own respective domains.  One examples would be establishing courts and prison systems (for state cases and federal cases).  Another example would be taxation -- both the federal government and state governments have authority to assess taxes.  Another would be holding elections -- national elections under federal supervision, other elections on the state level under state supervision.