I know that I have some talent for that, but I know that they must present themselves from A way that looks very professional, and I only know how to do it is on paper and pencil, once I tried to use a specialized drawing program but it did not give me, what if used is autocad, because I saw it at the university, I have seen the threads where they put art and it really is impressive.
You don't need to be a professional dancer to dance at pubs since focusing on having a great time is what matters the most. Similarly, you don't need to be a professional artist to take part in these entertaining contests.
You just need to draw to your heart's content and have fun while doing it which is what I usually do since I am not a professional artist myself and won a prize in one of their contests.
If you are participating for winning the contest then definitely you need to have some artistic skills but if you just want to take active part you can submit any of your work and present you ideas through it.You can see lot of members submitting normal artwork to participate in these contest so if you want then you can also do the same not to worry about anything.