Note that you may have to modify your new air filter by cutting out a section and applying tank sealant to make it fit around the accelerator pump protrusion. At least I had to do that for fitting to our MA4-SPA carb.
If you clean the filter per the instructions (not use of compressed or forced air for drying the media, recommended cleaning products and procedure, etc), then your filter should have a very long life according to the manufacturer.
Agree that it would be beneficial to seek help and guidance the first time around.