crazy things happening on my macbook pro 13" 2009

Why do i have xcode on my macbook pro instead of osx lion which i though I downloaded from the app store. I have many many files on my system as you see below. When i press the power button to shut down a remote debugger pops up with a name and IP address also it is as though my computer gets changed everyday files are added apps are deleted no menu items displayed cant access security features, cant access system preferences etc....

<?xml version="1.0" encoding="UTF-8"?>

<!DOCTYPE plist PUBLIC "-//Apple//DTD PLIST 1.0//EN" "http://www.apple.com/DTDs/PropertyList-1.0.dtd">

<plist version="1.0">

<dict>

<key>BuildMachineOSBuild</key>

<string>11E53</string>

<key>CFBundleDevelopmentRegion</key>

<string>English</string>

<key>CFBundleExecutable</key>

<string>Safari</string>

<key>CFBundleIdentifier</key>

<string>com.apple.syncservices.schemas.Safari</string>

<key>CFBundleInfoDictionaryVersion</key>

<string>6.0</string>

<key>CFBundleName</key>

<string>Safari</string>

<key>CFBundlePackageType</key>

<string>APPL</string>

<key>CFBundleShortVersionString</key>

<string>7534.57.7</string>

<key>CFBundleSignature</key>

<string>????</string>

<key>CFBundleVersion</key>

<string>7534.57.7</string>

<key>DTCompiler</key>

<string>com.apple.compilers.llvmgcc42</string>

<key>DTPlatformBuild</key>

<string>11E53</string>

<key>DTPlatformVersion</key>

<string>GM</string>

<key>DTSDKBuild</key>

<string>11E53</string>

<key>DTSDKName</key>

<string></string>

<key>DTXcode</key>

<string>0410</string>

<key>DTXcodeBuild</key>

<string>11E53</string>