Hello, I would like to add my two cents:
First and foremost, I recommend the OP to aim for Unity.
People often say that other engines are better for 2D games -such as game maker- or VNs -insert here your typical suspects-; but that's far from true. Unity can handle often better those kind of projects if you have the right tools or simply enough c# knowledge.
Not only that, but the online community to consult doubts is one of the broadest on the net.
I understand that starting from zero with Unity seems daunting... I know, I have been there.
My advice is to look for some good 2D RPG tutorial series at YT and follow it. I always recommend this kind of game tutorials because its content usually covers all the basics: basic chara movement, simple quest system, some physics, basic dialogs and inventories, etc. So once you finish those tutorial series you have quite a solid base.
On the other hand, I wouldn't try to go for modding or fan games about existing IPs. It's not worth to put so much hard work and effort in something you don't own 100% of it.
Rewarding other comments on the thread:
- Sadly, it takes months, if not years, to be good at it. No shortcuts.
- No, Unity is not a malware... It's been used by all kinds of big companies including the makers of Genshin and even The Pokemon Company itself... Telemetry is everywhere these days, including all cellphones.
good luck!