I'm going to put it more simply and focus on what really ends up mattering in the end instead of breaking down all the details:
1: Unity isn't really a ripoff of UE, but the developers read the same books. They're pretty similar. If you're comfortable with one, you're comfortable with the other.
2a: Unity is better for starting programmers because there is more of an API exposed to learn from and easily make use from without editing the source and compiling again like you must for many things in UE4.
2b: UE4 is better for more seasoned programmers, I GUESS, but mostly just if you're one of those guys that wants to rip out the entire rendering pipeline to replace it with something else, or use for an MMO that you need special things for. Unity has so much exposed that you generally don't need the source code.
3a: Unity is MORE EXPENSIVE if you don't get many sales and buy that pro version. And it really gimps you without buying it. :/
3B: UE4 is CHEAPER if you're making a free game, or don't make much money. It's way more expensive if you're making a lot especially if you have high overhead for server costs, employees, Steam distro fee, etc. (IE, they take 5%. But you spend 30% on employees, Steam takes 30% of your money, you have other misk costs that make up 5%. That 5% becomes 5% out of the 35% left which is now 14.2% of your INCOME)
4: Both seemingly allow porn games. UDK did not but they changed their licensing this time around. I asked like... a year or two back and didn't get a definitive answer from them, except "well the EULA pretty much doesn't say you can't" which I guess is actually kind of definitive? The problem is that if an adult game becomes bad for their image, I don't think the EULA offers you protection against retroactive change.
To me, it really comes down to cost. And UE4 is too expensive if you invest a lot of time and money in something. If you have hundreds of thousands of dollars up front for a license, you can save a lot, though.
But it doesn't seem like this is a thing for you. Why not play with both since you're learning?