Is this sentence grammatically correct?

[Vonhelmet]

I'm sure I was taught not to put commas before 'and'.

There's arguments for and against the "Oxford comma", but it's more a style choice than anything else these days.

I was always taught to put a comma where there would be a pause in speech, and so I put them before 'and' quite a lot. <== See. Could well be technically wrong though - a bad habit.

The origin of the word punctuation is to do with timing, as it was orginally developed for use in scripts and so on, so that actors knew how to time their speech. It serves as part of grammar nowadays, to help us with parsing sentences, but the timing of speech is still a good place to start with that.

Wouldn't 'The car is a Ford and 5 years old' be better?

Or 'The car is a 5 year old Ford'?

As Castiel has said, that wasn't my point. My point was an alternative example.

 

[Scrutinize]

regarding using a comma after and,

one of the points which i often critique when editing other people's reports is the use of this comma after an and. the reason for this is not because of grammatical preference or accuracy but simply because they usually use it to break up some enormous sentence rather than using a full stop.

regarding the first sentence,

I confirm that I am a player in good standing with my national association, and am a member of ____________

my take would be that

I am a member of ……………… and in good standing with my national association

or

I am a member of ……………….and a player who is in good standing with my national association

i am not really sure whether you would need to even mention the term ‘a player’ since this is probably implied by the correspondence and context anyway