1) What requirements are needed to have a SaaS website? I heard I need a server so I was planning on using Amazon's cloud service. But I hear I need something like an SSL (don't know what that is).
If you havent heard of SSL I think it would be fair to say you wont be capable of running any servers from AWS... They offer cloud based instances that you rent on an hourly basis.
I do not know what your SaaS would entail so its hard to say what you would need. Also your type of server will depend on the language it is written in. Generally you would need to run under Elastic bean stalk an EC2 server, with an RDS server for your database. These need to be fully supported, so you will have to learn or pay someone to do this.. The reason AWS is cheap as it is unsupported.
2) Should I look for a specific language that I want my programmers to program in? If so what would be the best language to save on time for it to be built?
SaaS means software is generally powered serverside (always exceptions), so the language is up to you and your developer. If you are serving it serverside then normally your clients would just use a browser to log into their software panel. Alternatively you can create native programs for all of the devices you want to use it, and connect to your database via the cloud. The first option would probably be cheaper for development to a wider audience.
Hope this helps but your vague description means its difficult to help more. Remember that ideas are the easy part, have some sort of implamentation rolling is what makes your idea worth money, expect this to cost some serious coin to get a *good* developer on board