Well, a good way to start is to look for DC comic compilations or trade paperbacks. These often group together related story arcs, making it easier to follow. Another option is to ask for recommendations at your local comic book store. The staff usually knows which titles are great for beginners.
Start with some of the popular and beginner-friendly series like 'Batman: Year One' or 'Superman: Birthright'. They give a good introduction to the characters and their worlds.
You could begin by picking up DC's 'Rebirth' series. It's designed to be accessible for new readers and reintroduces many key characters. Also, check out graphic novels that collect the early issues of your favorite heroes. That way, you get a solid start without having to hunt down individual comics.