Retinol mixing?

You really shouldn’t mix actives with moisturizer, cause the mix won’t be even and you might get irritation in certain spots. Better apply retinol on dry skin and then layer it with niacinamide, hialuronic acid and top it up with moisturizer. Or if you are just starting out, apply moisturizer, wait for it to absorb, apply retinol, and another layer of moisturizer. In that case use niacinamide and hialuron in the morning.

tbh I would recommend not mixing retinol with anything as it might irritate your skin, also hyaluronic acid and niacinamide work best if they're applied on slightly damp skin where retinol or majority of actives should be applied on dry skin so I really wouldn't recommend

if you have sensitive/dry skin like I do i follow sandwich method like I put a lightweight moisturizer than retinol and than top it up with a bit heavier moisturizer

i dont recommend it as hyaluronic acid is active ingredients

Yes they work well together. You should try the sandwiche method where you apply moisturizer first followed by retinol followed by moisturizer. Using this method lowers your irritation level.