There is definitely more that can go wrong than right. It's wise to study up and go in expecting very little and that way you can be surprised if you get good yields.
Do everything you can to not introduce pests. If I have been outside I shower and change clothes before going into my grow room.
Less is often more, the temptation to over feed, water too often, prune too much are all big no no's.
When you think it's done, wait a few more weeks. Harvesting early is something most growers do their first time. Don't do it.
Harvesting and drying is important and you should be ready for some hand cramps from trimming.