Here are some very good sources for Competition (AMC 8/Mathcounts, etc.) Practice that will give you an indication of how well you are prepared:
- AMC 8 Practice: Meeting from 2/23/16 that gives an introduction to what the AMC 8 is and what various topics are covered.
- Introduction to Proofs: Meeting from 1/10/17 that gives an introduction to proof-writing and interesting elementary proofs for various sums and combinatorial path walking arguments
- Symmetry: Meeting from 4/9/16 that instructs on the importance of exposing symmetry in all topics in math
- AMC 8 Review Session #1: Meeting from 11/1/16 that focuses on review of geometry and combinatorics
- 2016 AMC 8 Review Session: Meeting from 11/29/16 where we go over the last 10 questions of the 2016 AMC 8 Exam