If you sign, you are a newcomer after all, and you can't guarantee the speed and quality of your writing. Moreover, writing on other websites during the contract period is against the contract, and it is not good to change the pen name.
Moreover, big websites are really deep and there are so many good articles that they can easily become cannon fodder.
I am now working on a small website, Coolsmith, which has only developed in recent years. I feel ok. Anyway, I have never been in arrears with the manuscript fee, and the benefits are good. I automatically put it on the shelves for 70 thousand yuan, unlike other websites, which can't make much money.
In short, if the subjects are confident, it doesn't matter if you start on another website. Really can't. As long as you don't sign up, you can go to other websites.