Gday Ammie,
Dont worry about it at all seriously because you will find it will happen with every kid that starts a new game.All my nephews started football at 5 years old the first games were hilarious they have really no clue what the game is about it takes quite a few games for them to realise what they have to do.I will start my son next year or the year after and i know he will be the same as your son and have no clue and get bored lol.We live on a golf course so i called them for lessons for my boy he was begging me to play it.Anyways they said no he is too young he wont concentrate and may distract the older kids 8 years and above.That was pretty sad i felt bad for him but apparently can be hard for kids to really concentrate on anything before they are 8.Or Ammie he may not be into sport at all lots of kids arent and i guess you cant force them to like something if they have nil intersest.Give him a few more tries and if he dosent like it maybe give him another sport option.Self defence is good for kids i did that from about 8 years old till the end of high school at 18 yrs.It teaches discipline and also how to get out of awkward situations.Good luck im sure he will find something he enjoys.