My first attempt

Nick, Your pictures are a bit aimless, but that's fine you're just starting out, they show the camera appears to work OK.
So what to do now?

As other advise has stated, of course get the basics under your belt.
But I always advise to have a purpose. Nobody learns by just taking pictures. You need to have something to aim for, a particular effect or type of image e.g. high and low key portraiture lighting. And when you don't get what you wanted, you find out why. And that's when you start learning.

Secondly, do try black & white. When you can produce good B&W images, your colour ones will be great.
(The sole purpose of some images is the colour, but that's a different matter.)
Without colour to help define shapes, a B&W image is reliant upon composition, contract and lighting. Mastering these is easier without colour getting in the way.
And you might just get hooked on the timeless quality of B&W

Consider developing your B&W film yourself, it's not difficult and you don't require all the equipment and space printing needs. You can develop and scan your negatives in a couple of hours.
And you control the process. For example - image 9, you may have intended the negative to have been thin (underexposed) but the processors just average everything, instead of a deliberately dark print, that's what you get.

You liked image 15, so have a go at improving on it.
That monitor/TV some may say is intrusive, but it does provide bordering and focus attention to her face. However, that white "blob" draws the eye out of the picture, as does the bed linen below it. So try moving the camera up so that the TV fits in picture from top to bottom. And if necessary put some dark paper or tape over the "blob".
Next, the other bed linen on the right and lower are a bit too bright. Try shielding off some of the light from the window to darken these down. The shielding will have to be quite close, out of frame but not removing light from her face.
Try adding extra light just to her face. Direct light from a small mirror, but avoid harsh light (not generally good for female portraiture), spray deodorant or something on the mirror to soften the light. And be careful to avoid a shadow under her nose.
A wide aperture will shorten the depth of field (amount in focus) and focuses attention, but renders less quality. It may not be necessary to focus exactly on the eyes, but they must be sharp. Experiment

Good luck.

If you are only finding your feet in photography then you can't go wrong with film and a prime lens.

A Dale mat cost 175 upwards plus men cards charging, computing etc... when I plunge back to film I get rolls for a pound from the poundshop and have them processed straight onto CD for 2.99 are adds or tesco. Then you can play around with them on the computer.

The beauty of film is that it makes you think about every shot....