Walking cycles are difficult, especially when it needs a specific feeling of weight or style to it. There are so many parts moving relative to each other, and because we see people every day walking, it's easy to spot when it's "off", even if you can't pinpoint it. Given your little experience, you're doing really well though. It still looks great, I just notice the details because I have dealt with it myself so many times. It's only very recently I've started to feel more comfortable with walking animation myself, and I've still got a ton of room for improvement.