Hello! If you have an idea you love, draw and share it online and keep sharing about it, even if it doesn't get much response at first. A single post or few probably won't leave much of a dent, but eventually people will start asking you questions! And if you keep it up and make a bunch of stuff, people will have fun browsing through your old stuff even years later.
As for me, I just had a neat idea and I made some doodles and some comics, even though in retrospect the art quality is actually very subpar. Not to put myself down of course, I'm a good artist especially these days, I just mean that CORE!Frisk didn't capture people's hearts based on the quality of its artwork 🤣 People eventually started asking me questions, and those questions helped me to keep building the world and the character.
It's important to not get discouraged if you don't immediately get any attention, though. It doesn't mean no one cares about your work, it usually just means it wasn't able to reach a lot of people.
Use proper tags, keep it up, and for the love of god DON'T delete anything just because it didn't reach 100 notes by the end of the week! How are people supposed to find something that no longer exists?? There was this one artist I followed on Twitter and Pixiv whose artwork I loved and one day they just disappeared without trace, from all platforms. I still have their work saved as my phone wallpaper and it just makes me incredibly sad. It's why I never delete anything I made, even cringe stuff. Someone out there loves it!