Hi danielle,
I think the main question would be, how are you going to create this members database ?
Would you be looking at creating a script to manage and retrieve the data to your web pages? or use a pre-built script?
You mentioned being a database newbie...
My advice would be to find a ready-made script. You can find some here
www.hotscipts.com
Now, if that's the route you go, then you may not even need to use a MySQL interface like phpmyadmin or the one you mentioned. (I don't want you to pay for something you may never use)
You may want to spend that money on a good script
Most scripts are easily modified through a web-based interface, which means you won't even really need to use phpmyadmin or similar.