rubsal70 There is a lot of info in this thread, some of it better than others. Some of it contradictory.
If you are serious about improving your photography step away from the technology, and start to learn the basics. For instance....
1) The advice about a f/1.4 lense being "faster" (i.e. "better") than a f/1.8 lense is technically true... but you very likely won't see any difference. It is all of 1 1/2 stop "faster", and maybe not even that much once you take into account the rounding down the marketing department used to come up with the f/1.4 number. If you can get the f/1.4 lense for the same price, then go for it. But I wouldn't pay any more than $25 for that 1/2 stop. You will see more improvement in your photos if you don't have that cup of coffee before you shoot.
If you don't understand what a "1/2 stop" is, or why the coffee can be an issue... then that is a place to start learning. Hint: the coffee can introduce camera shake.
2) Learn what Depth of Field (DoF) is, and then learn to control it. Your current lense set up is fine for this. There are 3 ways to control DoF... Aperture, Focal Length, Camera to Subject distance. Focal Length and CtS distance can be interconnected... for example.... Shoot a head a shoulders of someone with a wide angle lense. Note the DoF. Now, change to telephoto and reposition yourself (subject stays still) so that you have the same head shoulders shot. Shoot at the same f/stop. DoF will be different, even at the same aperture, because the distance changed. You don't have to understand why this happens, just that it does and how it will affect your shooting. Depending on what you want to see in the image, you will choose your focal length and distance accordingly.
Use a tripod for both these shots.
If you don't understand why you can use the same aperture/shutter between lense focal lengths - then that is a place to start learning.
3) The other thing that changes between a telephoto lense and wide angle lense is 'compression' and 'expansion'.... That is why professional portraiturists use longer lenses. Never a wide angle (there are exceptions of course, but you have to be damn good, and you have to understand the basic theories) and rarely a 50mm. Unless you are working with a sensor smaller than full-frame.
In the days of 35mm film, the majority of fashion photos were taken with a 200mm telephoto. Majority of portraits were taken with something between a 90mm and 135mm. I have no experience with baby photography, so I don't know what the standard is there.
4) Get and use a tripod before you add lights, probably. Depending on your circumstances.
5) The most important tool are your feet. Use them.
I am happy to expand on any of these points if, in your learning process, you run into a wall.
I am a professional shooter, though now I mostly create art. But I have been teaching photography for a long time.
You will only learn by doing, and by doing a lot. The bit of advice about needing to take 1000 photos to learn a technique is about right. You do not need any new equipment to get started learning. As you learning process moves along, and you have a better handle on your style and what you want to do you will make much better purchasing decisions.
When you understand how and why things work in photography, then your equipment can do amazing things.
Good Luck.