You could do this simply with a batch file, here's something I quickly wrote up,

@echo off
ECHO ***Date and Time***
set datetimef=%date:~-4%_%date:~3,2%_%date:~0,2%__%time:~0,2%_%time:~3,2%_%time:~6,2%
echo %datetimef%
ECHO ***List Processes***
WMIC path win32_process get Caption,Processid,Commandline
ECHO ***CPU-Usage***
wmic cpu get loadpercentage
ECHO ***Memory Usage***
systeminfo | findstr Memory

It's pretty simple, you can tweak it to fit your needs but this meets your requirements. I also see that you want this data exported to a file so you can, output the contents of the batch file like this, batch.bat > Logs-%date:~10,4%%date:~7,2%%date:~4,2%_%time:~0,2%%time:~3,2%.log

You can view and download the file here as well

You could do this simply with a batch file, here's something I quickly wrote up,

@echo off
ECHO ***Date and Time***
set datetimef=%date:~-4%_%date:~3,2%_%date:~0,2%__%time:~0,2%_%time:~3,2%_%time:~6,2%
echo %datetimef%
ECHO ***List Processes***
WMIC path win32_process get Caption,Processid,Commandline
ECHO ***CPU-Usage***
wmic cpu get loadpercentage
ECHO ***Memory Usage***
systeminfo | findstr Memory

It's pretty simple, you can tweak it to fit your needs but this meets your requirements. I also see that you want this data exported to a file so you can, output the contents of the batch file like this, batch.bat > Logs-%date:~10,4%%date:~7,2%%date:~4,2%_%time:~0,2%%time:~3,2%.log