How often do you purposefully seek new opportunities for growth? If the answer is "never" or "rarely", start looking for ways to get out of your comfort level or little box. Raise you hand when an opportunity presents. VOLUNTEER.
Opportunities can be fleeting. I think of them like floating bubbles waiting to burst or golden sunsets (or sunrises). Neither lasts long and you must be on the "lookout" to notice them. Opportunities are similar. If an opportunity presents when you are not paying attention, it can evaporate.
Will there ever be another opportunity? Of course. Will the same opportunity present again? Probably not.
Let others know you are interested in participating, helping, working on projects through which you can learn. In the long run, you will want to take opportunities closely tied with your long-term goal. But if you are just developing skills, consider opportunities even if not directly related to that goal--they may help you network, learn new skills, or advance in some way.
Later, you must weigh the opportunity costs associated with each opportunity. But for now, start where you can!