Cryptanalysis

I think I managed to get the key but I can’t decompress the bz2 file. It’s showing me "Checksum Error" and said the file is corrupted. Some hints would be really useful for me. Thanks to you all <3

You should try the software named "7-zip manager" (or something like that) to open the .bz2 and open the raw file inside by text editor such as notepad.
If it does not work, your decryption might failed.

there is like literally 3,000,000 possibility ?
How is that even called crypto :’) ?