What does "嘛” What does it mean and when would I use it?
mean?

See a translation

sorry, what I said was in the case when you use 嘛 in the beginning of a sentence. Seeing it in the end of a sentence is much commoner, in this case, it's just a modifier, doesn't have any special meaning, but it'll give your sentence a special mood. Usually it will made the speaker cuter and lovelier.

I only recommend you use this to your close friends or when you're playing with someone, don't use this in formal situations. And also beware of the difference between "吗" and "嘛"，it's the same pronunciation but different meaning, 来嘛means "please come"（in a cute way），来吗？means（will you come？）.But on internet people would sometimes use 嘛 to mean 吗 because they're too lazy to type the correct word.