Patience is an essential attitude when starting a practice like tai chi. It's easy to get frustrated and feel that you should be further along or that you aren’t "getting it" as quickly as you think you should.
It’s important to remember you learning to move your body in new and different ways and it can take time to develop this new relationship to movement.
By offering yourself patience as you learn, you will be able to enjoy the practice at every point along the way, not wishing to be somewhere different, but accepting yourself exactly where you are at right now.
For your practice: As you practice the form today, however much or little of it you know, simply notice if there is any impatience present or a desire to want to progress faster. Make a mindful effort to allow yourself all the time you need. Be fully present in your experience, resisting the temptation to wish it was something different than exactly what it is. And congratulate yourself for the efforts you've made so far and for your openness to learn something new.