Stain only colors bare wood. If there is a finish applied, the old finish has to be completely removed for a stain to work.

Staining most bare woods is a whole lot more than slapping on the product. Sanding to the proper surface(different for different woods of desired results), correct pretreatment(to minimize blotching/streaking), and proper application are all equally important.

Removing a previous finish adds greatly to that process.

Gel stain is now popular because it is easier to use. Gel stain is actually a modified paint. The only easy DIY way to do what you want is to use a gel stain. But, using gel stains have their own pitfalls. The surface has to be properly prepared and the gel stain has to be applied correctly.

Can you do what you want to do? Sure, but you need to do some studying and practicing.