as a semi new flipper myself who has a few under my belt trust me something will go wrong always. Well not necessarily go wrong but things you thought were a certain price will always be more. Add a 50% contingency on your first one, you will be lucky you did. I guarantee things will go over budget and past schedule. If you can make some money at all on the first one that's a win.
Don't get too attached to the house during the process and remember you can never outsell the market. Never trust wholesaler ARVs. Price the house exactly at the comps if you over price it will sit and even if someone makes an offer, if overpriced it won't pass appraisal and you will have to drop it anyway.
Another thing about appraisals, they do not look at fancy quartz or granite or fixtures or finishes you will get zero added value for things like that. Of course some markets call for it, But make sure you really know what the comps look like, do not waste money on unnecessary things for no reason
Good luck!