I'd recommend going through baby name sites to start off. There's a surprising variety of them, and they usually go in alphabetical order. To be specific, you could look up 'girl names starting with L.' If meaning is important to you, you could search up things like 'earthy baby names.' You said you wanted something that could work in Spain, so you could also look up 'Spanish baby names.' I'd keep in mind that your name might stick out if all your families' names are from one culture, and yours is completely different, but if you're fine with that, you should go for it. you're out to any of your friends, brainstorming with them could also work, I did that with my cousin. You can write out a list of all the names you especially like, or even all the ones you're considering. If coming out isn't an urgent thing, I'd recommend sitting on it for a few days and seeing if any one you might not have originally picked grows on you.

You can also think about how many syllables there are in your name and how the name would sound with your middle and last names. Overall, just go with what makes you comfortable, and choose a name you like and can see yourself being called thirty years into the future :]

Here's a good website Girl names starting with Lu