Just as before any documents created in Google, docs, spreadsheets and presentations, do not count toward your limits, also any images smaller than 2048x2048 pixels are free. If someone shares a file with you it doesn't eat into your allowance, more info here.
If you need to transfer a large file, up to
Any files you add belong to you, if you share them you still own them, if you remove them they've gone. For more on sharing click here.
To check your allowance follow this link.