The page you linked to has downloads for 60-day Free Trials of the various VMWare products. That means at the end of the 60 days you either have to uninstall the product or buy it.
For your purposes, I would suggest you download VMware Player which is free for non-commercial use and the license doesn't expire. Get it here: VMware Player
There is no problem creating VMs using VMware Player and it will work perfectly fine with Ubuntu.
VMware Workstation has some capabilities that VMware Player doesn't such as the ability to take a "snapshot" but for the most part VMware Player is very useful.
Another free product you should consider is: VirtualBox
. It will also allow you to install Ubuntu in a VM.