Sorry, Bud. The names are mostly just advertisements and not necessarily useful for understanding the underlying philosophy.
American Liberalism (capital ‘L’) is fluid over time at best in its philosophy, and is actively shifting to further elitist interests from a less charitable perspective. It often prioritises corporations over people and cherry picks which cases of violence are or aren’t acceptable by the state.
American Libertarianism (again, capital ‘L’) is Anarcho-capitalism, which believes the world would be a better place if the state was bordering on non-existent, and companies were allowed to operate completely unregulated.
That is not significant a distinction for me to care to differentiate one from the other. They both are right-libertarian, are wanting laissez-faire capitalism with as close to zero oversight as possible, and are cutting taxes as low as possible by gutting public services. Whether one still wants to keep state-funded cops and fire departments is no longer relevant when the end results of both are corporate-nation hellscapes in my view.