I personally would like to spend time with it before i rode it, just to see what manners are like, if it responds to voice, if its impatient, laid back, quick to react to noise etc. That way you get some idea what it would be like to ride it. Also ask questions about spooking and its likes and dislikes. but then I don't like riding strange horses now, I like my comfort  zone. When is was a teenager (yonks ago!) i rode strange horses including appaloosa's with low head carriage over jumps! It was a challenge. Please take a bit off time with it, the horse will get to know you too. Hope this helps. x