Heya,
Try to pick up something fairly big and secondhand, the boards in the shop look so nice and shiny and its tempting to splash the cash but if you've got a lot of learning to do it's best to do it on something you don't mind taking a knock or two...or twenty!
I'm learning and I rented a lot at the start, but if you can find someone selling something cheap that's about 8' and made of the more durable materials (think epoxy rather than glass) you'll be laughing!
People on here are going to tell you the same thing, what works best is if you have something that maximises wave count and time, the more you surf the better so think BIG! maximum floatation and length, if that doesn't appeal to you then just remember this is the training wheels stage and there's no real fast way through it. A bigger board will make the waves easier to catch, will help you learn your pop up faster, will get your paddle fitness up to scratch and is perfect for catching the smaller waves which is what you're going to be learning on. Then if you buy a secondhand board you'll be glad you didn't fork out £400 on it when it's time to progress and get a shorter one.
And don't worry if others hate on the foamie you're riding or that big old BIC or NSP it can't stop the amazing feeling you get when you're up and riding and flying down that wave, that's really all that matters
Good waves and welcome!