Where It's the folder of app(Minecraft Launcher)?

Hello Afonso, this is Manuela!. I'm an Independent Advisor and community user like you ready to assist with this

If you don't mind, may I know for which specific game edition are you trying to find the folder?
Java or Bedrock?

Hello Cellou,my name is Marvina, I will be happy to help you.

I'm so sorry for what you're going through, here are some steps you can take to try to fix this issue:

Check your Internet connection. Make sure your MacBook Air is connected to the Internet and has a stable connection.

Try downloading the Minecraft launcher again. You can download the launcher from the Minecraft website.

Try launching the launcher from the downloads folder. Once you have downloaded the launcher, locate the Downloads folder on your MacBook Air.

Open the folder and double-click the "Minecraft Launcher" file.

Try launching the launcher from the Finder app. Open the Finder app and locate the "Minecraft Launcher" file. Double click the file to start it.

Sign in to your Minecraft account. If you are not already signed in to your Minecraft account, click the "Sign In" button in the launcher.

Check your version of Minecraft. Make sure your MacBook Air has the latest version of Minecraft. You can check your version of Minecraft by clicking the "Help" button in the launcher and selecting "About Minecraft."

I hope I have answered your question correctly, I wish you a Merry Christmas.

Sincerely,
Marvina.

Close your launcher. Navigate to your .minecraft folder and delete the launcher_msa_credentials.bin file. Then, run the launcher and log back in.

Troubleshoot the Minecraft launcher error: If you're encountering an error when trying to use the Minecraft launcher, you can try uninstalling and reinstalling the launcher or updating to the latest version. You can also try clearing the launcher cache by following these steps:

Press the Windows key + R to open the Run dialog box.

Type "%appdata%" (without quotes) and press Enter.

Delete the .minecraft folder.

Restart the launcher and try again.

In this case, please uninstall your Minecraft launcher. You can do this by going to Start > Settings (the gear icon) > Apps > Apps & features > Minecraft Launcher > Modify/Uninstall.

After that, please follow the steps below:

- Go to Start > Settings > Apps > Apps & features > Microsoft Store > Advanced Options > Repair, then Reset.

- Press Windows + R. Type TEMP and press enter. Delete all the files inside this folder. Repeat this step by typing %TEMP% and Prefetch. Delete everything on both folders too.

- Press Windows + R. Type WSRESET and press enter.

- Restart your computer. Open the Microsoft store and sign in with the same Microsoft account that owns Minecraft. Go to Library and install the Minecraft launcher again.

- Check your computer region/country and language and please make sure it is the same as your Microsoft account (https://account.microsoft.com/profile). Also check your time zone and date/time is correct.

Try to play Minecraft again and please let me know how it goes.