Having ideas is proof of nothing other than an active imagination. Serious people donate their time and energy to worthy causes. Someone with no experience finds a facility or organization that will take them on as a volunteer. That is something you realistically could do. Give it a shot.

The idea that you, yourself, are going to open a shelter and hire a nurse, doctor and psychiatrist is delusionsional. "Loosely playing with" ideas like that is unlikely to lead to you helping anyone. Be willing to "serve" in some useful capacity as a volunteer. You can even do things on your own . . . like collect second hand blankets, gloves, knit caps and distribute them to needy folks on the street. Make a large pot of soup and bring bowls of it to hungry people on the street. That's what it takes to be taken seriously. Your plan is more glamorous, but way less feasible.