Your targeting does sound correct, and it's an 'ever-green' niche 🙂 The promo images on your website are spot on - very romantic and fitting your branding. The featured products on your homepage don't really match the branding - they almost clash when you say you target couples in love, as you are displaying digital watches. It would be great if you showed couples' necklaces here, more engraved keyrings etc.
Also, the reviews at the bottom show very random selection of products, from backpacks to baby grows.
I'd recommend sticking to the niche you selected and remember about it when picking new products. Couples on love is a different niche than young parents [however wrong that sounds], yet it is. Young parents are looking to treat their child, look for safety products, feeding products etc.
What will help you is to create a target buyer persona: https://www.rockpapercopy.com/2169-2/ it will help discover who is the most likely to buy from you [their age group, gender, location, spending budget] as well as how to connect with them. Knowing this will help you significantly when building your website, adding new products, creating ads etc.
Also, one last thing - don't feel like you have to rely on the ads alone to get traffic. I know they are being recommended [for a reason], yet there's a ton of ways you can bring organic traffic [that converts] for free. You can learn more about how to do it in this video tutorial [it's $2.99]: https://www.rockpapercopy.com/video-tutorials/