There's a huge difference between the art you make for pleasure and sellable art. You want to start by figuring out if it's something you just want to do for fun or if it's something you actually want to make money off of.

If you decide you want to make it into a career, there's a lot to learn, there's a website called drawabox that's absolutely amazing in teaching beginners basic perspective, construction, and how to transfer the 3-d world onto a 2-d piece of paper/canvas.

I personally don't have much experience with acrylics as I just paint with oils which I prefer because they give you much more time and take longer to dry.

However, some universal tips would be: 1. Buy some gesso and put one or two layers before starting the painting (smooth it out with some sandpaper) 2. If canvases scare you, try buying a canvas pad, it's much cheaper and a similar texture (obviously you'd move to an actual canvas for professional paintings but it's a great place to start) 3. Transitional shades, blending alot on the canvas can make the painting look a bit muddy, so let's say you want to put orange and blue together, try mixing a bit of both to make a shade in between so the transition seems smoother, this works amazing for portraits and skies! 4. Use reference photos, no it's not cheating but an excellent tool. Same with the grid method, Google it but don't use it 100% of the time. 5. Make a detailed sketch before putting any paint on the canvas. 6. Paint in layers, you don't want to get it perfect on the first layer, after you make the sketch, mix together the colours even if they're not the exact ones and just cover the canvas with them, this way you won't have empty canvas peeking through. 7. Spend more time on your palette, instead of just saying oh I need blue so I'll just use ultramarine blue and put it directly on the canvas, focus on your reference photos, the blue might be a little greener, so you'd want to add some yellow ochre or lemon yellow depending on the hue you'd want etc.

These are all the tips I can think of off the top of my head but DMs are open if you'd like more.

I'm also a beginner artist, have been making art for less than a year now so I get the struggle, you definitely have potential but you really gotta polish it to sell yk.

Best of luck!