Hi Mor,
OK, I am an amateur so feel free to ignore me.
1. The 18-55 is the kit lens. This is an OK starter lens covering an OK zoom range. However as you grow as a photographer you will use this one less and less. What you will do however is benefit from using it to see where you naturally like to shoot i.e. what focal length you have it on most often.
2. The 18-105 is a slightly more useful lens as a walk about catch all lens. however, you need to keep your shutter speed up to keep good images as it doesnt have VR.
3. This lens is the one you want to learn to use. Although as a 50 on your camera which has a cropped sensor - APS-c not full frame, then it may feel a little tight at the edges. Don't worry this will start to make sense to you soon.
What you need to do is be comfortable with your lenses right now. You have enough there to start to get a feel for what you want to do. Google and youtube are good sources for info on learning to use the lenses but as a rough rule of thumb here are the focal lengths and their usual uses. Note, the rules of photography are there to be broken so these are guides not mandatory more a case of the lenses most useful for...
Shorter than 21mm for extra wide angle and speciality shots i.e. fisheye
21mm-28mm Wide angles usually for landscapes and some street
35mm - 50mm "normal" lenses general purpose great for do it all within reason, good for street photography, bit of architecture, for portraits towards the 50mm length range and also street depending on how close you want to get.
75mm-135mm close up work, portraits
200mm+ long distance, wildlife, sports events
Longer the focal length, typically more specific about the object/subject of your picture you are closing in on.
Now, here is the thing. These focal lengths are all for full frame. All lenses are marked for the full frame focal length so for example your 50mm is a 50mm on a full frame but on your camera model it will be more like a 75mm in terms of how tight the field of view is. You need to google the difference between full frame and cropped sensor to get a better description than I can give here. I recommend looking at this brilliant post from
@kallisti to get a feel for what it means.
https://forums.macrumors.com/threads/prime-lens.1952661/#post-22504148
I hope this is OK as a starter. Welcome and give us a shout with anything you need help with.