If you want to express that you just found out about something new or became aware of something, there are plenty of synonyms that you can use. Some common phrases that you can use instead of "became aware of" include "discovered," "realized," "noted," "perceived," "noticed," "recognized," "grasped," "took notice of," "apprehended," and "twigged." Each of these words or phrases has its own connotations, so you can choose the one that best fits what you're trying to say. Remember to always choose the word that most clearly and accurately expresses your intended thoughts and makes your writing more engaging.