Finished costume wondering if it passes

[Sierra Katrian]

For a first time costume it looks good. 

If you have time, I would try to mask, or remove the zipper on your bag, and anywhere else one may be noticeable. 
This is not a requirement, but modern items such as zippers can immediately break peoples immersion, and pull them right back into the real world, so we try to avoid them as much as possible. 

Also, I can't see the collar on your shirt, but keep in mind that edges were generally rough, or at least not very well finished as modern day clothes are. If you want to take it the extra mile, may I recommend punching some holes in your collar to make it tie up. 
Again, not a requirement, but it is fun to have everyone look like they came right out of a history book, or Game of Thrones.

Here is a video tutorial on how to make a very rough, very amateur medieval style shirt. For the quick fix, it works well. 
https://www.youtube.com/watch?v=XaH6v70h3ys