Is it safe to download and use mods?
Minecraft modding is usually safe if you follow some basic rules. Only use trusted websites like Tynker or MakeCode, and only download mods from websites you know are safe. It's also a good idea to make a copy of your game world before adding new mods, so if something goes wrong, you can go back to how it was before.
Here are some rules of thumb:
Never install a program if you don't trust where it came from.
Never run a /connect command in Minecraft except from mods that you have personally created.
Never run a command you don't understand.
Back up any work that's important to you! Work step-by-step and save different versions in case you need to revert.
Ask an adult if you're not sure.
If you follow these rules and stay away from unknown websites, modding can be a fun and safe way to make Minecraft your own.