As a beginner, developing skills at the instrument is probably the thing you want to focus on.
An upright, grand, or even digital piano with a good action will suffice for a beginner. Any decent instrument will do just fine. Realize that as you learn and develop skills at the piano, you will also be developing your particular taste in pianos. You will be able to make a far more informed decision to choose a more expensive instrument when you already have experience and are able to articulate qualities you wish to have in such an instrument.
I agree with the others above, a quality digital or upright for the time being. When you have more experience playing piano, then you will be better equipped for choosing a grand that suits you. Unless of course, you have found a grand in good condition at an amazing price, then go for it.
You mentioned composing. A digital piano with MIDI is very useful for using with things like notation software and a DAW. Some people will have a two piano solution: an acoustic for playing and practising, and a digital for working at the computer.