Help me pick domain name for my portal?

[Jake]

There are sites with tools that help you come up with fictitious names, including: wordlab.com, naming.net, wordoid.com, lingzini.com, namestation.com, some of these tools look up the domain name availability as you go.
Any name not already used in a .com web site name is probably not trademarked.

Godaddy has a Bulk Search option that allows you to try a list of several names ideas at a time.

Consider getting a pre-owned aged domain name, these tend to be able to earn search ranking more quickly, these are particularly helpful if you plan an aggressive SEO campaign, typically a new domain is on probation at first, subject to penalties if it gets too many backlinks too quiockly.