Can I put my owns adsense advertisment on my blog
No you cannot. No blogger initiated advertising is allowed on free hosted WordPress.com blogs and there is no upgrade you can purchase that changes that. Please read this http://en.support.wordpress.com/advertising/
do you create a redirection from the old domain name to the new one and can I export the old to the new?
No export is required for domain mapping and the bundle includes domain mapping.
Please read this section on bundles http://en.support.wordpress.com/bundles/and click through each link for the individual upgrades so your are clear on what is being offered.