How do you people genuinely start writing your first chapter or your first paragraphs? I have a sort of outline on how my story would play out but when it comes to the specifics (world building, dialogues, character intros), I find it hard to write it out.

As far back as I can remember, I always wanted to be a published author. However, I was discouraged by my mother, who said that nobody would read my stuff and I was too brief blah blah blah and so on.

My main question is, can you develop your writing style later in life? I'm an older gentleman, and I'm seriously thinking about putting pen to paper. I'm going to start off small with short stories and work my way up to a full-length novel or whatever.

Are there writing programs that help me get started? I have been using Grammarly with Microsoft Word for quite some time, and I think that I may need to begin exploring other options.

Any tips would be greatly appreciated.

Edit: Sorry if my preamble sounded too much like the beginning of Goodfellas. No plagiarism intended.