Here is what liberalism is
private property,consent of the government, free/mixed economy, secularism etc. there is the classical/conservative liberalism and the more progressive liberalism which is what liberalism in america means to most people
leftism is anti capitalism/ pro workers rights
common left wing ideas include
social ownership, free healthcare, Mutual Aid, volunteerism, workplace democracy, unionization, and workers owning their work
There is authoritarian leftism but just ignore those idiots (we call them tankies)
alot of leftists take the social elements of progressive liberalism.