As adults we have a hard time allowing ourselves to be a beginner. We are an adult after all, shouldn't we be able to do things right and perfectly the first time?
I can't help but laugh at that statement. Since when does anyone do anything perfectly or just "right" the first time anyway? Not me!
As you are beginning your journey into making art it is ok to be a beginner, In fact, I am giving you permission right now to be a beginner, you can make mistakes, you are allowed to make "bad" art, and it is ok to practice, a lot.
All the great artists did not churn out perfect and amazing works of art that went right to the museum or gallery. Every artist from Georgia O"Keeffe to Picasso started somewhere and I imagine there are sketchbooks filled with ideas and drawings and practice paintings and piles of discarded work that well, stunk.
Making art is a process, it is a journey. Every single thing you make leads to the next thing you make. Your skills build, you improve, and your ideas evolve. That's why it is a journey and a process.
There is no such thing as a perfect painting, if you feel satisfied with what you created that is good enough. If you feel frustrated with what you created make another one and let the last one be a learning experience.
And by the way, how many of us are going to end up with art in a museum or gallery anyway? It is also perfectly ok to create art because you enjoy it, because you are proud of it as a personal accomplishment, and because it is a positive outlet for your self expression.
Enjoy the journey, trust the process, go and make stuff, you have my permission.