Well I’m not going to say it’s good but for a first try it’s not that bad. The main problem is that the legs and the body are too long. Also the lines, when you draw a line, you must try to do it in a single motion intead of a bunch of short ones, you drawing will look cleaner and more polished.
 
On the other hand, for a first drawing with no reference I must say you got the anatomy well, the hind legs save for their length are well done and the neck conect correctly to the head.
 
Keep drawing and I’m sure you will improve.

@Minus  
Thanks this one was just me bored with a bored and a marker at 3am, lol. I made another one where I was really trying pretty hard and it took forty minutes if you want to see it here is the link https://derpibooru.org/1643577

If you’re actually trying to get better at drawing, use references. I made sure to draw a really accurate pony in the first page of my sketchbook so that I always have that to use a reference at all times. It never hurts to have something to remind you what something looks like.