For some reason I cannot collect xp and i cant level up.also when I entered my world the whole world went black and all I could see was animal but there were no blockd to be seen.

Have you tried a full reinstall of the game?

Backup any data you don't want to lose, then try the following:

1. Backup your MinecraftWorlds folder (if you want to save your worlds) (Device storage > games > com.mojang > minecraftWorlds)

2. Uninstall Minecraft

3. Delete the com.mojang folder (Device storage > games > com.mojang)

4. Reinstall Minecraft

5. Run Minecraft and if it works restore your MinecraftWorlds folder

Sometimes a clean install of the game will help with these kind of issues.

You might find the following links helpful:

• How to Back Up Worlds

• How to uninstall and reinstall a game on Windows 10

Quick Links:
📓 Issue Guidelines – 💬 Mojang Support – 📧 Suggestions – 📖 Minecraft Wiki

Cleaning up old tickets: This ticket had been set to 'awaiting response', but has not received a response from the reporter (~3 months+) so is being closed as Cannot Reproduce. If you feel this is still a valid issue then please comment, or create a new ticket following the Issue Guidelines which includes steps to reproduce the problem.

Quick Links:
📓 Issue Guidelines – 💬 Mojang Support – 📧 Suggestions – 📖 Minecraft Wiki