Just like Chinese characters have a specific order to their lines, hangul letters also have proper stroke order. While no one’s going to give you a dakbam (probably) if you draw the bottom line before the top, it’s a good idea to learn stroke order. If you’re going to learn how to do something, why not learn how to do it correctly?
Although at first it’ll be difficult to remember the proper order, and writing with stroke order will slow you down, it’s worth it. Once you get the hang of it, those hangul letters will all but fly off the tip of your pen. It just takes a little practice.