If you're an adult and beginning piano lessons for the first time, or restarting after a while, then you need to avoid these 2 major traps when it comes to learning piano.
The first TRAP is Discipline. So as yourself, do you have a proven track record of discipline? Because if you don't, it's going to be an issue. Even if you're paying for lessons out of your own pocket, trust me when I can say you'll be able to find a way to skip practice sessions. Even though I had adult students paying me good money, they would consistently show up unprepared. They wouldn't even have the discipline to sit down for 5 minutes a day! So if you're not disciplined, make sure you get this area handled.
The second TRAP is much more difficult because they're Bad Habits. They're unconscious behaviors we've picked up since childhood, or bad learning habits which have been conditioned into us (from school). There's no easy answer for this, the only activity I can suggest is what's helped me: Self Reflection. This might be an uncomfortable activity, but sit down for 10-15 minutes every day with a pen and paper. Really think about your entire life up to this point. What are things you believe? What behaviors are you holding you back? The hardest part is they're unconscious, so you might not even KNOW what's holding you back. But any psychological "baggage" you're able to let go will really help lighten the burden or heaviness you might feel when it comes to learning piano.
For more general tips on how to get the most out of your piano lessons, make sure to check out How to Find a Good Piano Teacher