If you bought designs before you became a member you do have a download area. Go to My Account, then My Files. If you did not purchase any designs before you became a member then you will not have that option in your account. You just need to download each design on the design page. If you stop paying for your membership you will not have a record of what you downloaded and you will not be able to re-download the files after your membership ends.
On all designs except the daily freebies you have the option of downloading and/or sending them to your email. You may want to send them to your email for a backup plan.
You have to download one design at a time. There is no central download area where all of the designs you have chosen go. After you pay for your membership, you can download everything on the site. Welcome, to cute, I'm glad that you are here!;)