SOQL limits are cumulative across an entire transaction. You likely have a trigger or other flow somewhere that's triggering the error. Unfortunately, you're going to have to learn how to read debug logs and do some profiling.
⚙️ -> Developer Console (new window) ➡️ Debug ➡️ Change Log Levels... ➡️ Add/Change (top row) ➡️ Add ➡️ Set all columns to NONE/ERROR, PROFILING set to FINEST ➡️ Add ➡️ Click Profiling ➡️ Done.
If you've followed these steps appropriately, you should see this:
Notice how the General Trace Settings for You table shows Profiling under DebugLevel. That means you've set it up correctly. Click Done to finalize your changes.
From here, you can just run your flow, and when you get the error, use the Logs tab to open up your log. You'll get a text file containing information about total CPU usage, query usage, etc. You'll just need to check this profiling data to see where most of your queries are being used.
Note that this may be one of those cases where the "victim" is usually an innocent bystander. For example, if you have a trigger that uses 99 SOQL, and the flow runs afterwards, it may have only used 2 queries, but it gets the blame, since it is when you ran out of usage limits. You'll need to profile the entire transaction to figure out what went wrong.