According to the author of the book of Proverbs, this means that if people try to convince you to do something wrong, you should say no and not follow them. It's like when someone tries to tempt you to do something bad, it's important to stick to making good choices.
Proverbs 1:10: My son, if sinners entice thee, consent thou not.
The verse advises not to follow sinners, emphasizing moral integrity. Some see a contradiction with the idea that everyone sins, suggesting it's impossible to completely avoid sinners. However, the advice focuses on not being influenced by wrong actions rather than avoiding all people who sin.