Read p. 148 in your textbook. Practice a few of the exercise questions from your book. If you need extra help, check out the link.
It'll help you identify adverb clauses if you look out for the subordinate conjunctions listed on the page--it might help to memorize these, just like you may have had to memorize some of the other key words earlier in the book.
Also remember: adverb clauses, like adverbs, describe verbs, adjectives, or other adverbs. They tell when, why, how, how much, and under what condition something is or is happening.
Example: After the game ended, we quickly drove home.
"After" can be used as a preposition, but in this case it's introducing a clause because there is a verb included ("ended"). "After the game ended" is a clause telling WHEN they drove home. (Ask yourself, "'After the game ended,'" what?" to see what the clause describes. [In this case, it's that they drove.])
When you feel comfortable, start the homework:
Create a Google Doc to answer questions #1-15. Name each adverb clause and its subordinate conjunction (which will always be the first word in the clause). If you have trouble making a Doc, you can print out the handout, write on it, and upload a picture of it. You can also just do it on notebook paper and take a picture of that. Don't forget to submit this assignment!