There are a number of sources that you can use for finding great images for your blog.
Google is an excellent tool which you can use to find royalty-free images. There are thousands of images available here which you can access through the following steps:
1. In Google, select "Images" and type the search words that you are looking for.
2. Select "Tools"
3. Click "Usage Rights"
4. Select "Labeled for reuse"
Alternatively you can look at the following sites which provide just a small selection of free-to-use image sites:
- Freepik
- Pixabay
- Pexels