You need to make a positive and thoughtful comment. Saying bad stuff might affect them. Introduce yourself to the person, make a friend. Tell them what you enjoyed about their post and what they need to improve from. Give a helpful advice. Make them appreciate your comment. Last but not least ask them a question about their post or who they are.
Last week we learnt how to put a link in a comment.
<a href="insert URL here">Insert display text here</a>
Where it says insert URL here You delete and paste the link
Where it says insert display text here, You delete and write what you want it to say e.g "Click here to listen/watch/read"
Can leave a Comment with a link?