So I was wondering how do I access the ultimate web builder package since I did pay for it

You can download your purchased software on the Downloads section of your account, here's more info: https://www.ultimatewb.com/downloads-area .

Do you have web hosting yet?  We will need to update the namservers for your domain name to point to your web hosting.  Then you can install the software onto your web hosting: https://www.ultimatewb.com/installation .  We do have web hosting packages available at UltimateWB: https://www.ultimatewb.com/domain-names-web-hosting .  All UltimateWB web hosting packages come with free installation of the UltimateWB software you purchased onto your web hosting.  Then you could start designing/creating your website by logging into your website admin panel.