Here are some helpful tips when learning to surf:

It doesn't matter about what the shape the board is as when you start off surfing as you should be focusing on standing up not doing manoeuvres and tricks.

The board should be long and have a lot of flotation.
Some examples for boards that would suit beginners are:

Foam boards are ok but you will have to upgrade eventually. They have flexible fins and a soft material. So if you fall off you cannot get fins slashed or knocked out by the hard surfboard. a good brand of foam boards are softlite.

NSP the brand would be a good board to learn on as they are made from a stronger material then fiberglass. so this means the board would last longer.

Sideways are a  surfboard manufactoring company that make boards. These boards are made in Indonesia. This means the board can be sold really cheaply.