Hi @reverland,
Your English is just fine, dont worry about it.
The problem with things like web servers are there are so many things that could be wrong and they may not be to do with lisp.
The other problem is that it sounds like you are trying to learn about two things at the same time; making a web serve and programming lisp. This is not a problem but don't confuse not understanding lisp with not getting a web server up and running.
It sounds like the output being sent is being read in as plain text rather than html. These options are set by mime types.
The first thing I would do is use telnet to connect to the server and see what response you get back. This will show that lisp is working and sending information out on the port (we know that already because some web servers are showing information). But it will also show you the text your web server is sending on a successful connection.
You can google the responses that a web server should accept and respond to. A good starting place is here
The you will need to use a little detective work and trial and error to work out where your problems are.
Good Luck with the learning!