Those are charts, but color charts rather than cables or something with different stitches. You need to look into how to do color work. Here is the link to the page with free videos here at KH. LINK Scroll down to “How to knit with 2 colors at a time”. The two most common techniques for color work are stranding or intarsia. I think I would use intarsia for one of these, especially the 2 colored star on a contrast background. The other could be done with stranding I guess and drop the CC color like intarsia at the edge of the star each time. I’m not sure how it would work out. I’ve not done a lot of mixing intarsia and stranding. One project that I tried it on I didn’t like how it came out all that well, but it was quite different.
Intarsia is easiest worked flat. Look into how it is done and see if you think that would work for your project. Then try some small samples and see how it goes. I know there are probably a lot of other videos and tutorials on the internet now that you know what to look for.
You could also do the design in duplicate stitch or on the 3 color design do the white background and the use the color on the outside of the star for every stitch of the star using intarsia and then go back and do the 3rd color with duplicate stitch. Duplicate stitch is a method of embroidering over the knit stitches so that it looks knit in.
Each square on the chart is one stitch. Worked flat you read the chart from right to left and the alternate rows left to right. If you were knitting in the round you would do each round right to left.
Here is something I have in my saved links about intarsia in the round. LINK I’ve never tried it or even investigated it very far; it may not be that hard. I notice this person offers 4 ideas for how to do it.