Do not attempt to open only the first part, as it will likely appear empty or corrupted.

7zip file with numbers on it like 001 means that you only have a part file of the whole compressed file. Microsoft Learn How to Open and Extract .001 Files - Microsoft Q&A

To view or extract the contents, you need all parts of the archive (e.g., 001, 002, ...) in the same folder.

The exact contents are unknown without extracting the file. It could contain anything, such as a dataset, game files, documents, or media.

To help you further, do you have the other parts of this archive (like .002 , .003 ) in the same folder? How to Extract .7z.001 files - Microsoft Q&A

Based on the file naming convention, is the first part of a split 7-Zip compressed archive .