I was wondering if anybody could explain how to make a marketing bot

Like vitaminoo for example

i dont remember but maybe u have to buy the bot

vitaminoo will show you how to make one
if you give him 500$

Read this I guess. It was literally the third tutorial on the list, next time I would advise you go there instead.

It doesn't really tell you how to code one...

Oh. Sorry. I didn't realise. Well tbh you probably need to know lua script to start off with or just buy one like mattkit said. I will try to find a better tutorial for you.
-----
This link was in one of the replies to the link I posted. It seemed pretty thorough.

The trouble with coding is you need to learn how to code first then learn what you need to do separate. Otherwise if a problem occurs you're pretty much screwed.

Learn to code with python and how to use .json and .py files (Find your preference) then try and establish this knowledge into an automated bot.
Also what nobody has covered here is time, if you intend to have it running 24/7 like Vitaminoo then you'll need a pretty beastly cooling source otherwise you're getting a toasted CPU/ PC fast.