u/Heavy-Stand-6715

Hi i just bought a vanity covered in a maple veneer, im a beginner and just want to change the colour/refinish it a bit darker. theres no damage just some sun bleaching and scrapes from wear and tear. is there anything i should watch out for/tips and tricks to do this right? i heard i should be careful with sanding, should i sand it by hand rather than a sander?anything will help! i can post pics too if needed