The correct and complete sentence is:
"Andrea is the team leader of the state level of DECA."
Explanation:
1. Andrea is a member of DECA.
2. DECA stands for Distributive Education Clubs of America.
3. Andrea is the team leader of the state level of DECA.
4. The sentence does not mention her being a group leader at the national level, only stating she is at the state level.