You first logged in to Server Fault less than half an hour ago, at 21:30, so I am not sure why you would believe you had any reputation. There don't seem to be any other accounts on Server Fault which also used your IP address, nor any other guest postings.
Most of the remainder of your questions have already been answered in depth on the network meta site:
- Reputation 10 to post imagesReputation 10 to post images
- How does "Reputation" work?How does "Reputation" work?
- What is the association bonus, and how does it work?What is the association bonus, and how does it work?
- Why would any meta site have a minimum reputation of 5?Why would any meta site have a minimum reputation of 5?
In short, you gain reputation and privileges independently on each site in the network. The fact that you know a lot about programming doesn't necessarily mean that you know anything about professional IT, for example.
Once you receive 200 reputation on one site, though, you will receive a 100 reputation bonus on all other sites, which eliminates most of the new user restrictions.