If you are driving a car then the Gôl Centre is a good shout. 10 minutes straightforward walk to the ground. Has a healthy mix of home and away fans.
£5 to park and you get a voucher for the bar for the same amount.
If it’s quiet your kids can have a kick about on the 5 a side pitches.
https://www.golcentres.co.uk/locations/cardiff
It’s run by proper football people too.
Some great memorabilia from their away trips with Wales