I am trying to install Oracle SOA Suite 11g but I face the following problem during installation. There are some prerequisites marked as failed. I am wondering why the overall result of the check is not executed. In addition, I have a problem starting the SOA managed server later.
I cannot see the "SOA" folder here
Clearly, if you ignore the checks and SOA does not appear something is broken. You need to tell us your OS version and make sure you adhere to the installation instructions here. My guess is you're on some linux distro. There are many files that need to be installed in many cases on linux to make this work.
I suggest, unless you have to install directly on your OS, to use a prebuilt virtual image to get up and running quickly. SOA Suite 12c prebuilt is here. Install virtual box (free) and then follow download instructions exactly. Here is 11g.