there are several ways to go about creating one's first fursona. some people use the animal* they like the best, others use traits they have in common with animals (physical, personality, or mental), others use symbolic animals.
*By animal, I mean any creature, or combination of creature, that is either real or imaginary. For example, a mix between a red fox and a unicorn is perfectly acceptable.
Once you know what animal you want, you can figure out what you want them to look like. That's when a ref sheet comes into play. There are a bunch of free lines/bases out there, or if you have money you can commission someone to draw one for you (there are some people who will do it for free, but you shouldn't rely on that). OR if you have the talent you can draw it yourself.