you can try the paypal sanbox for test puposes . for that you should create a merchent account and buyer account , you can register it in paypal site to get a sanbox account.
If you want to try both at the same time (sandbox paypal, paypal online ) try it in two different site access. that would be a better idea
Thank you for your reply but what I meant was I wanted the user to pay me online using paypal OR just fill in the form with details so that I get an email and I can later contact him and complete the order.
You can try the ezpaypal extension or ezauthorise , there is a tutorial about ezauthorize in article section in ezsite. that information will be helpfull. if you do not need page redirection as it happends in paypal , you can try ezauthorize .