There’s a whole lot of varied advice out there on what projects to include in your PDF portfolio. But ultimately, it all depends on the type of role you’re applying for.
As a general rule, you should only include the work you’re most proud of. Be selective and avoid adding any projects for the sake of it. Aim to keep your selection below 10 projects, and try to balance different approaches and outcomes, making sure the projects you choose fit the brief and role advertised.
If you don’t have loads of experience just yet, remember that employers are most interested in new voices and fresh perspectives; they’ll want to see an eagerness and hunger to learn. So even if you don't have any published or commissioned work just yet, you can include self-initiated projects, rough ideas, drafts or experiments. This shows that you’re interested and keen to learn.