Hi Michele,

Ivana and Su.Ki. are right. It looks like the website you're using just translated literally from Italian. 

If you want to know whether a phrase is actually correct, natural and in use, you can put it in quotation marks and do a search of news articles.  The only times I found "before of" were examples which had the words in separate phrases. For example, "We've heard this before, of course, ..."

If your level is anything around intermediate or higher, you should be relying more on proper dictionaries instead of translators. ;)

Those sentences are all incorrect, Michele. In fact, that whole webpage is complete garbage. It looks like a combination of bad machine translation and non-native error.

Don't believe everything you find on the internet!

Ivana is right. You should never put of after the words before or after.  

I need to train before playing a match.

I need to go to the dentist before going to the hairdresser.

Unlike the Italian equivalents ( dopo and prima, I guess?) which are adverbs, the English words after and before are prepositions. And like all prepositions, they are simply followed by a gerund, or ing form.

Don't try to impose Italian constructions on English!