It is possible to learn to fly on your own but there is a long standing joke about doing so: "the average first flight of a novice (alone) is about six seconds!" Trying to do this without an instructor will make you a proficient builder (misc repairs) but won't do much for flying. If you are persistent enough on your own, you will be able to take off, fly and land consistently. However, there is much more to learning proper flying skills than just bringing your plane back to the ground without crashing.

Regards,