No need to preach. Most people at this stage in their deen want to feel understood. Your job is to give them that feeling.
A few points to keep in mind.
- Don't overwhelm them with rules and regulations. Tell them to take it easy and to take it day by day. Ex. "Don’t worry, you have a lifetime to improve. Start small"
- Speak less and ask more questions
- When you are asked about things, don't give them everything since you also want to teach them to learn directly from scholars. You may get them into the habit of asking people who are not qualified in all religious matters and it can cause issues in their journey to Allah ﷻ
Read this powerful excerpt on how to listen effectively