>>95947662 (OP)On the off chance that OP is going to check back in this thread:
Ignore anyone who tells you that you need to railroad players. That's bad advice.
Read the Alexandrian's advice on running mysteries scenarios, especially the 3 clue rule, and the stuff about node based scenario structure, but those articles should link to a bunch of different articles on how to structure a mystery. His book also has the advice in a more organized structure, but the articles are free.
If you can, read a gumshoe system game. Trail of Cthulhu has good advice for scenario level structure, Night's Black Agents has good advice for campaign level structure/tackling big conspiracies, which sort of play out like a big mystery solved by solving a bunch of smaller mysteries. Both of those are by Ken Hite, I'm not sure if he's written any specific articles or done any talks specifically about his style of mystery writing but it might be worth seeing if he specifically has anything on YouTube about. He calls it "the ocean of clues," that phrase might help you track down good information.