You can often use other people’s material in your studies, but there are limits. The safest approach is to use your own work, use material with clear reuse permission, use only what you need, and always acknowledge the source.
This page explains the main copyright questions students usually have about coursework, images, library readings, AI tools, and sharing work online. If you are a postgraduate research student working on a dissertation, thesis, or publication, you should also read Copyright for Research.