Hello Boris,
Let me guide you on your way to learn more about IT, Servers, Databases and Networking. First of all you need to know that programming is required to be learnt, even if you are just going to enter any of these fields. Programming, is a way of talking to computer, training it to do what you want to do. If you want to be a system admin, server admin, database admin or no matter what. You need to understand how to communicate. You cannot make computer to do anything, if you don't know how to tell it to do something.
IT department
Information technology, you are required to work around with data, strings, numerics and other similar stuff. If you don't know how a computer communicates (see Networking section), how do you convert the data into stream of bytes that can be sent to other devices. You are not going to even understand anything about IT.
IT is not just about clicking some buttons, to send email. Instead you need to understand how email is sent, what protocol is used, how are streams used and other similar concepts. You need to understand this one first.
Administrating
Ok, this one is a bit confusing. An administrator is just someone who handles everything in that field. If you are a database admin, you admin what is going on in the database. Again, if you have no idea how database works, what commands are to be issues. You are in vain, you won't be able to admin it. So, learn programming.
Database Admin
It is the job of database admin to create the schema, creating procedures in which the data will be stored in the database, how many requests should database server handle and so on.
Server Admin
This is same as to what is discussed above. You just handle the server. Email server, web server, FTP server etc. They are all one of them, if you don't know how these things work. You can never control what is going inside of them. So, first of all learn these protocols (Email works on SMTP protocol, web runs on HTTP protocol, FTP runs on FTP protocol)
SQL and Databases
SQL is just the language, that you can use to trigger some commands on database server, such as SELECT commands to get the data from databse. INSERT INTO command to insert records in the database. Database is just the software that stores the data in it in a compact and efficient way. There is nothing very much difficult in it. :-)
Networking
Networking is a very vast field in computing. Computers communicate through networks, networks are designed in a way to allow two or more computers connect and share their data with each other. There are many protocols, designs and models working. OSI model is one of the most used models in networking.
In computer networks, only streams of bytes are sent over the network. So, all of the images, audio, video and text data are converted to their representing bytes and are transferred over the network. You need to understand the byte representation before you can be an expert in networking. You need to learn the protocols, you need to learn how data is transferred and so on.
Pro tip
I would suggest that you learn these things, try to search for content on C# Corner, or Google for an article for these topics. Try using them, get some errors, try fixing them. :-) It would take more like 5 years to be an expert. If you know something about a framework, try digging deeper. Never think you have reached expert level until 10 years of experience.
Good luck buddy.