If you have the Dropbox desktop app linked to your Dropbox account, then all of your files are already on your computer. If you don't, you can link a new computer to download all of your files. If you have selective sync enabled for any folders, you can edit your selective sync settings to download those files to your computer as well.
For information beyond the files that you store on Dropbox, you can sign in to the website and go to your account page to see account information like the name and email address for your account. You can also view the IP addresses of connected sessions, computers, and mobile devices, as well as apps connected to your account, from the security tab.
If you've communicated with the Dropbox technical support team, you can sign in to our customer service portal to get a record of your communications with us. If you're not able to sign in, use the Forgot password link at that page — this won't affect your Dropbox sign-in credentials in any way.
If you would like to submit a data access request, please contact us at privacy@dropbox.com with the words "Data Access Request" in the subject or body of your message.