"I love learning" is used when you're focusing on the process of learning.
Example: "Mary loves helping her mom. They clean the house together, wash the windows, prepare the lunch." Here it's about the process of helping.
Both "I love learning" and "I love to learn" are correct, and the difference isn't that big. However, the second form (using the infinitive) is more for talking about the facts, and not the experience.
Example: "I prefer to check the reviews of the books, before buying them." Here it's not about the process of checking, but the fact that you do it.
I hope it helps!