Are we allowed to do business on chol moed? Like transporation business and sign contacts and agreement to carry people in vans?

ב"ה Shalom, Firstly, I should point out that your question only reached my desk after Pessach. There are specific criteria for which kind of work is allowed on Chol Hamoed. I will not get into all that now, apart from the specific criterion of what is called in Halacha "tzorchei Rabbim", which perhaps a proper translation would be "public necessity". Meaning since people may travel on Chol Hamoe'd and not everyone has a private car, public transport, such as buses, taxis and vans are "tzorchei Rabbim" and are needed to get people around and the drivers may get paid for this work on Chol Hamoed. (See: שמירת שבת כהלכתה חלק ב, פרק ס"ח :ב, חוט שני יום טוב וחל המועד עמ' ר"ג' , חזון עובדיה הלכות מחול המועד עמ' קע"ה , כי בא מועד הלכות חול המועד עמ' ע"ו, קיצור מקראי קודש הררי חול המועד ) All the best