And, welcome to the shooting world!
Please don't take this wrong, but the first thing you should do is take a NRA certified Hunter Safety Course. Even if you never plan to hunt anything, take the course! Before you spend any money on a gun, take the course, please!
You will learn basic gun safety, handling, and general firearms information. Right now, by your own admission, you barely know anything. This forum can teach you many,many,many things, but you have to know what it is you need to ask, and the Hunter Safety course will teach you that. And it will give you a good solid knowledge base for your future decisions.
The Ruger 10/22 is a great gun, one of, if not the best common semi autos. But, being a semi auto, it is a little more complicated than manually operated repeaters.
The Marlin is basically a bargin basement gun. OR entry level, if you prefer. A good gun to start with and learn on for low money, but not one you are likely to be happy with for a lifetime. Fortunately, there is always someone looking for a good starter gun, and when you do decide to move up from the Marlin, you can get easily get something for it. Probably not a lot, as they don't sell for a lot, brand new, and used value is always less.
Take the course, get some literature, learn the basic things you need to know, the ones that tell you how much you can learn, and in what direction you should aim your inquiries. You can do searches in the forum, and read lots and lots of stuff that others have asked, and answered, that will help you out as well. The trick is not to fall victim to information overload.
A .22 with iron sights is the place to start shooting. Scope can be added later. learn the basics, Safety, positions, safety, sight alignment, safety, trigger control, breath control, safety, and did I mention safety?
As you get started, come on back and ask more questions, somebody's always here, and we all began sometime. Don't be embarrassed with you don't know yet, we all started out asking a lot of the same questions you are, or will be.