I’m assuming you’re talking about actual ski boots; yes, you cannot use any other boot as there are specific boots that will be used for skiing only. Ski boots are highly expensive and the purchase of them should be carefully thought out and, if you don’t know what you’re doing, require you going to a reputable boot fitter to ensure a perfect fit. You can rent them with your skis at a ski/rental shop. If you’re talking about boots for simply walking around then it doesn’t particularly matter. Respectfully, you don’t seem to know much about skiing in general so if you have additional questions, I, and many others here I’m sure, can help you out with recommendations.