These questions may already have been answered but since you asked me...
Do all hosts, sell domain names?
Most do, possibly all. Its been a long time since I've seen a host that doesn't. I see someone has highlighted the risk that you may only lease the domain name if it comes free as part of the package. Personally I always buy the domain name from one company then get the web hosting from another.
Do all hosts use wordpress packages?
No. Some of the budget hosts offer deals including WordPress. Some hosts give you an empty server but make it easy to install WordPress. Others target more experienced users by giving an empty server and leaving you to install whatever software you want on it.
What are the other types/names of packages?
WordPress was built to handle blogs although many people use it for websites. Others include Joomla and Drupal but there are many more.
Can you tell me some more hosts' names please? (For comparison)
Search Google and you will find loads.
What is the difference between;
.com
.co
.net
.org
They are all top level domains. They are supposed to be used as follows:
.com - a business
.co - a Colombian website
.net - internet service providers, network operators and similar
.org - non-profit organisations
In practise they are often used for other purposes. For example, .co is often used by businesses, particularly technology startups. I would go for .com if it is available and ignore the rest. However, if you only intend to sell in the UK I would go for .co.uk (which is the UK equivalent of .com).
Given what you want to do with your website you may need to pay someone to set it up for you. What you are proposing is more complex than the kind of thing you can get by simply using a WordPress hosting package.