They don't NEED a routine.
Sometimes babies will slot feeds and naps into a predictable pattern.
Sometimes the parents will follow a structured routine, some with great success, some less so.
If you are happy with the way things are, then carry on - don't feel you have to do something because your mum, or anyone else says so. Your baby will do just fine if you carry on as you are.
However, if you would welcome a bit more structure / predictability to your day, there is no harm in gently encouraging your baby down that route.
You can either follow a routine from a book, ie Gina Ford, or the Baby Whisperer, or you can find your own pattern that suits you and your baby.
Strictly IMHO, a bit of a routine can be a good thing. to start off, I would try and start your day at the same time, maybe 7 am, even if this means waking your baby to begin with.
At that age, feeds should be no more than 3 hours apart, and your baby shouldn't be awake longer than about 1 1/2 - 2 hours before having a nap.
The Baby Whisperer's EASY routine is good, if you want to give it a go, as it follows a regular pattern rather than being set by the clock ( it'll make sense when you see it.....)
However, your baby is still very young, adn you mihgt decide there's plenty of time for all that in the future.
Whatever you decide, do what's right for you and your baby. Trust your instincts and don't feel pressured into doing something because someone else thinks it's a good idea.
Your baby will be fine whatever you decide.