Any advice for research experience from professors and turning over a new leaf?

I was in an internship at a small STEAM startup for 6 weeks, during which I began feeling bad vibes from the HR and the supervisor after various issues.

For starters, I documented the reasons why I was late for 3-5 minutes a few times (extremely terrible weather, illness which I got a doctor notice for) and yet the supervisor was immediately concerned and put me under an improvement plan.

I was alleged to have used inappropriate language In late June by a guest. The supervisor gave me no details of the alleged incident, and I was not aware of this until some days ago. I did not use inappropriate language then.

They claimed there were concerns about "Collaboration" and "Teamwork" affecting company culture - none of my colleagues have ever had any concerns about this. In fact they applaud me for creating a competition STEM course for kids and are grateful I immediately take feedback. This just seems like a big contradiction and some personal issue I lost, considering the supervisor gave me no details.

I left the company and didn't work. I couldn't stand the reputational damage I had suffered. To add insult to injury, HR ruled in favor of the supervisor.

How to turn over a new leaf? Thank them for the mentoring, office environment? And how to use part of my research project for other things, e.g. about economic instability and how investors and small businesses should watch for it?