Which skincare product I should not use with retinol
In general you'd want to avoid other chemical exfoliants and even some forms of physical exfoliation. Retinol is powerful enough that doubling up on products with a similar effect is more likely to cause harm. That means no AHA/BHAs.
You also don't want to use drying products. Retinol is notoriously irritating as it is effective. That means stay away from astringents and *drying* alcohols.
Also, steer clear of benzoyl peroxide. Again, it's drying but also causes oxidation. You can see that in effect if you apply peroxide to blood (it will turn brown and bubble). In addition to potentially irritating your skin, it could oxidize and ruin the effectiveness of the retinol. The major takeaway from avoiding all these no-go ingredients is you don't want to reduce the benefits a retinol can provide by over-exfoliating, over-drying, and oxidation. You also, presumably, don't want to walk around with facial dandruff from flaky skin or tight, burning, itchy skin that makes you want to tear your face off.
Lastly, we should discuss those drops. A product can have "retinol" in the name or description, but it's very important to pay attention to the form of retinol in the ingredients. The further removed from its active form, the more processes have to occur in the skin to make it active and beneficial. Thus we encounter a twofold problem: the formulation has to actually get the retinol ingredient into the skin AND the skin has to be able to effectively convert it to the active form, retinoic acid. Doesn't mean it's useless, just that some people might have better results choosing a product with a different form. If you're already aware of all that and are seeking the benefits of both a retinol and that of using a potentially gentler form, ignore my spiel. :)