For all the middleware you use, whether SDL, SFML, DirectX, OpenGL, PhysX, Unity, Unreal, whatever, you need to know what those licenses require of you.
SDL, SFML, DirectX, OpenGL don't require you to show anything at startup. You still need to read their licenses (or get someone to explain them to you) because they may require something else - like making your game opensource, for example, or prohibiting commercializing your game.
Every library you use has a list of "You can't do this", "You must do that" requirements. Licenses are legal agreements: For the convenience of using a specific library, you agree to the terms of that library. Some libraries have more than one set of licenses, and you get to choose (or pay to use) which one you want.
Thankfully, most libraries use the same four or five licenses, so once you learn what those few licenses mean, you automatically understand what is required/blocked by almost any library you encounter.
Some of the licenses have very acceptable terms. Whether those terms work for your particular project depends on the nature of your project.
In general, the MIT license is very friendly, and the LGPL has a few constraints but is perfectly acceptable. GPL is to be avoided like the plague when it comes to games.
Still, they have a few minor requirements that you need to understand: None of those three require you to show logos or do any extra programming work, but they do have a couple things they don't allow you to do, and a few things you are required to do.
Right now you are probably banging your head on the desk saying, "I just want to make a freakin` game! How'd lawyers and laws and governments get involved!? This is dumb!"
In actuality, it's not hard to learn (everything looks confusing the first time you see it!), and you don't have to take any law courses to understand it. You can learn it piece by piece as you go, it's not something you have to really study or waste time on.
All you really need to learn is, "For <license A> I can't do X. Gotcha.", "For <license B> I have to include q and y", and "My goals aren't compatible with <license C>, so I better not use that specific library."
Just minor "rules" you gradually pick up for commonly used licenses - you don't actually need to learn how to read the legal jargon.