Thanks for posting your question to the Dropbox Community, @LPN.
If you want to make sure that your files are fully synced, you can check the sync icons next to them to confirm their sync status.
If you see that they're currently online-only, you can select them, right click on them and choose "make available offline".
This will sync them, so you can then unlink the computer from your account and uninstall Dropbox.
I hope this helps, but let me know if you have any questions.