I am assuming that you have a MAME folder
That you have extracted the content from the MAME version you downloaded (preferably the exact same version as the rom set version you have).
That you have placed all the rom zip files inside the "roms" folder
For the ini creation, if you are finding the step too difficult, try placing this attached ini file in your main MAME folder (where the main mame exe file is)
Launch MAME and try double-clicking on any game from the list (dont worry about the audit or the status of the file). Try with a common one like 1943.zip or similar; see if it launches. If it gives you an error of some sort, paste the image with the error here. If it works fine, then just follow the LB tutorial steps to import all the roms and assign the mame exe as the emulator.
ini:
mame.ini