Fun fact, learning to digital paint sucks. I wanted to share some of my observations from my time learning digital painting, and also some things that I think would help ease the pain a little. Hope it helps! I've actually already made a Youtube video on this, but I feel like I express myself better in writing.Becoming a painter is an incredibly slow and frustrating process and the worst part is that it takes time. It's always the tip that artists give to beginners, and I think it's the tip no-one wants to hear; 'just keep painting', they say. 'It will come.'
*deep breath*
NOOOOOOOOOOOO.
Unfortunately, it's true. I thought I would preface this post with that hard truth.
As I said though, there are things to ease that process. Painting in itself should be an enjoyable experience, but there will always be times of burn out or hating your work. As you start out, I would urge you to paint lots of different topics (firstly, as photo studies) and see which ones you keep coming back to, don’t worry about a ‘style’ for a few years. Just focus on learning to paint. Every new thing you try to paint- tree, rock, sky, skin- they all have their own characteristics that you have to learn to emulate in 2D. That's really hard!
Go outside!

Find places, people, colours, textures, things, that you like. And paint them! Either on location or photograph them first. The style thing- that is, what you paint and how you paint it- will begin to take care of itself if you paint what you love and keep painting it.
Keep in mind art that you love, and reference it. But don't copy. Be your own artist.
Choose topics you enjoy and make life easy for yourself- choose good reference you can paint (it might take time to learn what this reference is). Look for lighting, foliage, textures etc, you can replicate. Avoid manipulated photos, or images that are noisy and don't read easily. Try squinting at the photo and see if it still makes sense when blurry. This is where painting master studies comes in handy- working from pieces where decisions about value, colour, noise have already been made might make for an easier ride (or, depending on the art, a much worse ride).

As time goes on begin to introduce topics you find more difficult. This might be stuff you have already learned that you struggle with from past paintings.
It's worth mentioning that everything I have talked about above refers to working from photos as studies. That is the first stage in learning to paint. Study, study, study. Below are some more generalised observations and tips that might help.
When beginning to dabble in more imaginative work, 3D blockouts can be super helpful to solidify your knowledge of pespective. Use a mix of good reference and experimental 3D to reach your goals. You can also experiment with different lighting, compositions and angles this way.
I notice that a lot of artists starting out have a habit of scribbling with smaller brushes to add colour or texture. Try working with larger brushes and mixing up areas of blended colour and rough paintwork to create nice texture. And though it might be tempting to use lots of brushes you bought from your favourite artists, try to pare down your textured brush use to brushes that are actually useful. Your opinion on useful brushes will absolutely change over time, and the best thing you can do is maintain awareness of this happening. Try to not drown in brushes, I use about 5 overall and make my own if I need one. 1+ for geometric brushes like square, oval, round, and hex brushes!
Speaking of brushes, it took me a long time to figure out flow vs opacity and when it is useful. I almost never manually edit opacity, instead opting for pen pressure opacity. However I edit flow a lot as it can modify how much 'paint' comes off your brush and therefore how easy it is to blend. Lower flow = easier blending.
Value is another big struggle you will encounter with painting, and something you need to be aware of when doing studies. Working from black and white images to familiarise yourself with the values and then stepping up to colour can be a good test. Also taking an image and replicating it using only 3-4 value groups. For me, I find that I tend to go too dark and too light in a painting, and do not make the most of the abundance of values on the spectrum. You do not need to use all the values on a spectrum of 1-10. Values 4-7 for example may have just as much impact.
The last thing I want to talk about in this vastly condensed post is colour. Colour is arguably not essential when compared to good values and drawing skills, but colour does have a huge impact. In my art I would say I over-rely on colour to carry me. Regardless, colour is fun and also hard! If you have ever done a mentorship with me, you will be familar with me saying 'push' the colour. What I mean by this is take the colours you have in a painting so far and analyse them. How saturated are they? Are they feeling a little flat? Can you add a little bit of pink here or green there to help pop the colours more? It can be as simple as colour picking from your painting, upping the saturation or hue shifting a touch, and then adding this back in for variation.
Experimental colours in Photoshop using Layer Modes.
I highly recommend experimenting with layer modes such as Lighter Colour, Pin Light, Difference, and many more to see what they can add. Either work with a layer of one colour, or copy and collapse down all layers of your painting, change the layer mode, and move the layer around to see the cool colours it picks up.
Final thoughts;
Your painting is going to have an ugly phase.
Embrace it and try not to weep.
Rendering takes a long long time.
If you think it’s done it’s probably not.
You’re going to hate painting at least one time PER DAY probably.
Have fuuuuuuun byeeeee!
(This blog is from my Patreon, see here; https://www.patreon.com/anyatheartist)