On its own, there's nothing wrong with wanting to learn as you go along, but you need to form your own learning group or tell people ahead of time that you're going to be learning as you go before they invite you.

If you don't understand why, consider the analogy of a series of math classes: Everyone starts at a basic level, say, addition and subtraction, and works their way up to, say, calculus. When you join a PUG of people who know the fight, and you don't, it's like you're walking into a calculus class knowing only addition and subtraction and you're asking to be taught your way up to calculus while everyone else waits for you. Now imagine by the time you start to grasp calculus, the class lets out. The next day, another student shows up knowing only, say, basic algebra, and they need to be caught up. This continues day after day, and the students never get to learn or practice any calculus. This is what you're doing when you join PUGs without knowing what to do ahead of time.