best way to see if buying a horse is right for you

Hi.

I have just started riding a very gentle Icelandic.  Am a 55 year old woman with confidence issues (on a horse).  I would like to buy a horse, but would like input on the best way to go about it.  I have only been riding (and taking lessons) for two weeks, and don't want to jump into something involving a living animal to quickly.

Any advice on a good way to go about it would be appreciated.

Thanks.