Which American accent though? :P We've got a few different ones over here, and they don't exactly sound the same.
Why American accent as opposed to British or Irish or Canadian or any other country that speaks English natively but isn't American?
Several reasons.
The way I've always seen it is that
American accent is like, just a regular English. (I am not talking about accents that are fairly distinguishable, but what you hear in most movies. Or at least what I hear.) So to speak American English, I imagine I'd only have to lose my Croatian (similar to Russian accent, but less rough, so to speak), and pick up some general ways of pronunciation of some letters/phrases/etc.
As for
British, I would have to speak English perfectly, to be able to pick up that pure British accent.
Take the world "Far" for example. In Croatian accent it'd have the rough R, and to switch it to American, I'd just have to smoothen the R part, and it's already sound a lot more like American (Right?), and to switch it to British, I'd have to say the entire word differently, from the R that is not even pronounced, to the "A" that to me, doesnt even sounds like an A, but more like an O.
As for
Canadian, I cant even hear the difference between it and American :/
And as for different American accents, I can rarely notice the difference.
For us with totally different accents, it's a good thing if we can just hide our own accents (which would then sound more like American accent), let alone picking up something like British or Australian accents. If you wish, I can send you a YT video of our politician speaking English, and you'd hear how horrible it sounds lol.
Honestly
I really wish I knew someone whose English is native language to have them correct me and so I could improve my speaking, but I can only rely on TV and Youtube for now.
I believe I can speak in American and British accent, or at least some of it, but I heard people who thought the same but their English was s*** so what do I know lol.