Sub domain on Zoho

Hi, I am beginning the project work, and I am trying to get a website going. I have two questions:

1. Can I use a website with a .tk domain.
2. If I use Zoho to make a site, can I use a subdomain like .zohosites.com? I am attempting to setup my site on Zoho, but all of the.com or.org or .us domains cost money