Best Way to come to Dehradun from Delhi for travelling(not originally from delhi)

Hi Everyone, I am looking for the best and the cheapest way to travel dehradun from delhi most preferrably from bus Can anyone suggest me some ways (I am not from delhi) so that i wont get scammed. My travelling date is 30 jan 2025 Should i book my tickets from now or some other time I will be coming from train to delhi then i will go to dehradun (train also may get late so please suggest) me the best options.