The female flowers need the male ones to pollinate them, so it’s best to leave some. You could use a small brush to help the process by hand pollinating them. If the cucumbers are dropping off you may need to feed your plants with an organic liquid feed. It’s also been rubbish weather, so if the temperature drops overnight too much this can affect the fruits. Our advice would be to persevere as we are all hoping for a warmer rest of summer!
I hope this helps!