Hi had a business idea on Shabbos but I didn’t speak about, is there any minhag or inyan not to go about it
I am not aware of any such minhag not to do something about it. Regarding if there is an inyan, there is a gemora (Shabbos 150b) of a certain chassid (very pious person who does more than what is required) that he saw a hole in his fence and he thought about fixing it on Shabbos. The he thought to himself, that since he thought about fixing it on Shabbos, he is not going to fix it. He therefore left it like that, and a miracle happened and a Tzlaf tree grew over there and covered the hole. The Chasam Sofer on that gemora says from the Arizal, that the chassid in this story was R’ Yehuda Bar Ilaei, who was a gilgul of Tlafchad, the person who was mechalel Shabbos shortly after Kabolas Hatorahin, and this act was a form of teshuva, to go to the opposite extreme. It says that when a person does teshuva out of love, the sin becomes a zechus, so he was given a Tzlaf. The name Telafchad, stands for Tzelaf chad- one Tzelaf.
Getting back to your question, this was an act of a chassid, but for ordinary people, personally I am not aware of any written inyan not to. If you want to do it as a personal hanhaga, that is up to you.
Have a gmar chasima tova, and an abundance of parnossa.