Are you from the UK living in Spain. I used to live in Spain for years and I don’t think I have ever dated women in my home country or in my language. Flirting with others in a different language isn’t anymore awkward than general flirting (in fact I find the thought of flirting in French, my native language, horrifyingly awkward).
My advice is don’t overflirt.
I LOVE women who are confident and proactive but I hate women who are cocky or think that I will fall for the cheesiest pick up line (I won’t) or just because they are pretty/show an interest in me.
I approach women a lot in gay bars etc... but I don’t go to them and call them “babe”/ “guapa” or whatever. I acknowledge the fact that I don’t know them and therefore pet names is not appropriate and might irritate them more than anything.
Talk to them like you would someone you would want to befriend. If the attraction is there on both ends then it will flow naturally.
I don’t prepare what I am going to tell the person and I don’t use pick up lines or cliché sayings. I just adapt to the situation etc.
And sometimes I will compliment the girl on something and then walk away, which might seem counter-intuitive but usually what happens is that because we are still in the same bar we will continue to bump into each other throughout the night and it becomes easier and more natural to keep on talking without it being awkward or force onto the other person. (You know like when you spot someone at you stop everyday, and you don’t know them but you feel oddly comfortable around them and it wouldn’t be weird if you started talking because you have just seen each other in the same space a lot, well like that.)
Barcelona and Madrid obviously have the biggest gay communities and Barcelona has a massive lesbian festival each summer (which I plan on attending post Covid), so going there for you could be really nice and help you find a good queer community or at least help you start flirting in an environment where people want to flirt/be flirted with and meet new girls.