While it's very nice that you like to watch movies, that has no bearing at all on becoming an actor. That won't help you at all.
And play-acting alone in your room is not only useless, but a very bad idea. You could be learning all sorts of really bad habits which will be very heard to break. And just because you love this play-acting does not mean that you would even like real acting - it's totally different.
And I'm sorry, but I really don't think your plan is any good at all. You need to start by joining a really good acting school - one you can attend every week, at least once a week. Random classes and workshops here and there aren't going to help you develop.
You also need to start with stage acting. That's how almost all actors start out, as it's where you learn all the really important things and grow as an actor. And while you do that, you should be performing regularly with a good community theatre, so you can put what you're learning into practice.
On average, it takes seven years of training and gaining experience before any genuine agent would consider signing you.
Those showcases where they charge you loads of money to act in front of lots of agents - they're mostly just scams. Sure, they invite agents, but hardly any actually turn up, and there's no guarantee that they'll be any good.
You need to know a lot more about the realities of acting before you pay out a ton of money on scams.
So get into a real acting school - and be prepared to stay there for years. Join a reputable community theatre and find out what real acting is. Take singing and dance classes as well - they're extremely useful.
And then aim for a place at a university/drama school for a full-time, three-year, degree-level course.
After all that, real agents might consider you if you turn out to have great talent.