how to import xmls and save responses

You have to use Groovy scripts to do this in SoapUI free version. Get a list of file names then submit contents of each file in the request step.

First Groovy step to get list of files:

def fileList = []
new File("C:\\requests").eachFile { f ->
 if (f.isFile() && f.name.endsWith('.xml')) { 
  def filename = f.name[0..-5]
   fileList.add(filename)
 }
}
if (fileList.size() < 1) {
 testRunner.fail("No request files")
}
context.put('fileList', fileList)

Followed by request step with this in the body:

${=new File("C:\\requests\\" + (context.get('fileList')).last() +".xml").text}

Followed by another Groovy step to remove the file from the list, write the response to a file and loop back to the request as long as there are more files:

def fileList = context.get('fileList')
def fileName = fileList.pop()
def response = context.expand( '${Test Request#Response}' )
def f = new File("C:\\responses\\${fileName}_Response.xml")
f.write(response, "UTF-8")

if (fileList.size() > 0) {
 testRunner.gotoStepByName('Test Request')
}