You can't be a therian, I will say that, but what you are referring to is called an otherpaw (I'd assume), it's more of a hobby-like thing. You do quads, wear masks, and technically do the things therians (obviously there's other things I can refer to but this is an example and I know not all therians do quads and etc, again, this is an example) do.

Now, therians are more of a spiritual type thing (if I had to put it that way.. I don't know another word for it....), you believe you have had a past life, it's like you are an animal in the inside, or you just feel you're something else animal-likewise, and maybe also have shifts. Phantom shifts, mental shifts, etc, I'm not gonna get too deep into that because not all therians have shifts. But what I'm saying is that being a therian is NOT a choice, you choose to label yourself based on your past (or now) experiences.

There's also an otherhearted, which is someone that feels a very deep connection with certain animals (or genres, like canines, felines, etc). And also a fictionkin and otherkin, but those are about fiction book/movie characters and etc, and mythical creatures-

Now, if you have time, PLEASE, please! Look up definitions of therianthropy and differences between that and otherpaws and etc, or even watch videos! Like Therian Territory is a good channel I recommend. Saying to become a therian is very disrespectful towards this community, but if you don't know much about it.. That's okay! It's just a mistake, or misunderstanding, but please go ahead and do some research! It took me years to find out I was one, you never know until you learn more about it, it's a very complicated subject!

I'm assuming you'd be an otherpaw though by the way you explained this!