There are a lot of useful sites out there to help you with your lessons. Check these out!
Englipedia was the biggest resource for English-teaching resources until its sunset in 2018. The archive won't be around forever, but give it a check if you like!
Japan's premiere clip art site. All pictures are 100% free, but you'll need to search in Japanese.
This site takes recent world news articles and generates exercises based on them. Useful for students high school age or older.