Guidance required - Automate a greenhouse

Hi I'm about to start a project for a friend of mine, he is a vegetable producer and want to automate his greenhouse. I have few experiences with Arduino (I'm mechanical engineering student) but I may need some guidance.

I have already checked few projects on hackster, instructable and others and most of the parts are already figured out but I have few questions about the software/communication part. A software to manage the system might be really good but I don't know if its too complex for my knowledge but the project absolutely needs a datalogger.

From my research, generally the projects use a non-editable and non specific software, a very complex IoT system that seems to complex for my experience or no software at all. I'd like to use a editable user friendly software that I can program myself or with the help of a super DIY project!

I hope my post is specific enough and even if I struggle only with this part I welcome every recommandation!

Most projects posted on those sites are open source so I don't see why you think the source can not be edited.

Sorry for the confusion but what I wanted to say is some projects use an already programmed software like GreenIQ for example that doesn't correspond to all the features that I want to add or they built a software from scratch an that is to complex for my knowledge t this time.

As your friend is a producer, and I assume you want to keep your friend, this is the time for you to step down from this project. You're bound to make mistakes in setting it up, especially as you apparently don't have the skills yet, and those mistakes can become really costly fast.
Or help him implement a ready-made commercial solution. That way if there's a system failure at least it's not you that killed his crops.