Human Resources is really an umbrella for so many different areas... there are Generalists and HR Business Partners; there are specialties like Total Rewards (compensation and benefits), HRIM, Culture and Engagement, Employee Relations consultants, Talent Acquisition, Communications, and more. Each of these offer a full range of growth potential, and often interact with each other and provide opportunity for cross-learning and advancement. No two days are ever the same!
HR also partners across other areas of the business, including Finance, Communications, business leadership and and others. It really does offer the opportunity to see and learn so much.
I agree with the recommendation above to chat with those in the field and find out what drew them to HR, and what keeps them here.