One of my brilliant teachers - the one who inspired me to become a teacher myself - always pushes her students to work hard and find their edge, while also gently reminding them that where they are today is where they are meant to be. "If it was supposed to be easy, it would be called Yoga Perfect," she would say as I struggled to keep both feet afloat in my crow pose, or to pike up into headstand (poses I still struggle with and work on regularly, by the way). Her point here was to push us to our absolute edge and then a little more, slowly pushing further and further with every practice until eventually we could hold that pose that once so intimidated us
You won't likely be able to tackle a crazy arm balance or wrap your legs around your head during your first hour (or week or month or year or decade) of yoga practice. It's about working your practice over time and slowly progressing as you become stronger physically, emotionally, spiritually. Those "party trick" poses can be awfully fun to post on instagram, but don't be hard on yourself if they simply aren't in your practice yet. Your practice - as it is right now - is exactly how it is supposed to be. You will progress over time if you continue to come to the mat and give it your best effort.
Perfecting a sirsasana headstand or side crow pose can be a really empowering moment if you've been working toward that goal, but even when you reach that aspirational pose, there is always a deeper place to take the practice. It's important to remember that, while some of the yogis and yoginis practicing around you may have a more advanced practice than you, they are still working just as hard on their own practice. The level of effort required to hold a modified side plank for one person can be the same amount of effort required for another to strike a side plank with tree legs. We are all on our own journey in our asana practice, just as we are in life. Honor where you are, and commit to continue challenging yourself.