Everyone has their own process. By this I mean the great Plotter vs Pantser debate that pops up in writing groups all over the place. Just because one person swears by a certain process, doesn't mean it will work for you. Take your time, write often. You will soon develop your own process, whether it's spending months researching every detail and ironing out the entire story before you ever put pen to paper, or going in entirely blind and letting things happen. I personally am a world-building pantser. I come up with a setting, ironing out most of the details and history, then find the cool stories that I can tell in it. I blame playing D&D for nearly 30 years.
Just Write. It doesn't need to be good. It doesn't even need to be something you intend on showing anyone... It can be as half-assed as you can be bothered to make it. Doesn't even need to be a full story. This point is simply to get you in the habit of writing. Waiting for inspiration is like waiting to win the lottery. This is fine if you want to remain an amateur, but if you want to be a professional about it, especially if you want to make a living out of it, you need to build the habit.
Draft 0 is your friend! Something I've recently come across is the idea of a "draft 0". This one is mostly geared towards pantsers but plotters can probably make good use out of this too. That is, where you just word vomit all over everything, with no intent to use any of it in the subsequent drafts. Make mistakes. To hell with proper grammar. Can't figure out how that scene's gonna play out? So what, put [Protag busts out of this trap by doing something totally awesome!] and move on. When you finish, you've already figured out how it's mostly gonna work. Now go back and write it properly. Maybe there's some stuff in there that's not so bad with some editing.
Oh, and that's another thing. Stuck? WRITE NOTES TO YOURSELF! In the advice above I mentioned using brackets or paragraphs for getting past where you're stuck to come back and write later. In the same vein, this is also good for notes to yourself. I use square [ ] brackets for "this scene needs to go here", curly { } brackets/braces for notes when I'm on a roll and can't tab over to my notes file, and parenthesis ( ) for things that, as I'm writing, are going to need definite editing or I'm not 100% certain I want it to play out that way.
Speaking of notes, I'm going to advocate something commonly used in television. Invest in a Show Bible! A show bible in television and film is like the go-to Master Document. It's got all the character profiles, designs, set decisions, photos, notes, plot lines, plot twists, background information that may never actually be seen or heard by the audience, etc etc. It's the primary reference file. Plotters probably already make these without realizing them, but pansters.... My dudes... My brethren... I cannot stress this enough. As you're pantsing your way through your story, and you're building character and world elements, backstories, etc.... WRITE THEM DOWN! I cannot begin to tell you how many beginning and even intermediate writers I've seen have just... so, so many continuity errors because they didn't write details down. Make a show bible document. Chronicle literally everything.
And finally, I'm gonna finish with a bit of advice for plotters from a pantser..... Don't be afraid to let your characters out of your grasp. Yes, I know. It's kinda scary letting your characters and plot run off with itself. It goes against everything you've ever had planned... But to quote Bob Ross, There are no mistakes, just happy accidents. Which is to say, let them run around a bit. No one ever needs to know this happened. Heck, you may like what you come up with while in a good flow better than what you had planned. If you don't, just delete it and go back to business. If you do, enjoy it. The only person that needs to know your story went off the pre-destined rails is you.
And that's pretty much all the insight from writing for 24 years I've go that hasn't been covered already.