Here are a list of self hosted applications you can use as a Pro Se (Self Represented) person that are professional and help organize your case.
Document management is always key to a good case. Paperless-ngx is a great DMS that can be run in a docker container.
Electronic signatures and Email tracking is another must have. We have found the opensource Docuseal on Github to be a great solution for this.
Make sure to have an email account from Gmail or some other service that is dedicated to your case or your legal communication as it will help when your licensed attorney needs to see what you have collected pre-litigation.
Stirling-PDF is a great free server application to manage PDF documents. You can split, combine, watermark all your evidence.
Nitro-PDF is a paid application but is worth it to edit and maintain PDF documents if you have a lot of them.