Here are some example web applications where you can use Reactjs:
- Blogs (Gatsby)
- Business websites
- Rating websites
- Membership sites
- e-learning modules
- Personal websites for self-promotion
- Job boards
- Business directories
- Q&A websites like Quora
- Non-profit websites for collecting donations
- Wikis and knowledge bases
- Media-centric sites like YouTube
- Auction and coupon sites.
I recommend this React Course by Intellipaat to learn React Js.
Also, watch this video on React Js: