It looks external, meaning that a bug or caterpillar came along and had a superficial lunch; and the resulting scar is what is left.
But it could be Angular Leaf spot which is caused by disease that is spread by watering topside of the leaves.
Other than that, there is something malnourished-looking about the shape of the leaves and the thickness of your planting bed. The coloration sort of is thrown-off a bit; a bit chartreuse which could mean a Nitrogen deficiency. Perhaps some systemic fertilizer with a bit of sulfur might clear this up. The sulfur will transfer to the leaf material making it unpalatable to the bugs that happen by. Some folks are lucky and have a natural sulfur in their water systems (usually wells of course).
OK, wishing you luck. I do hope you get some fruit and that this vine is able to support it to maturity. I would definitely look into fertilizer even if it is the basic 10-10-10 for tomatoes.
Do not spray directly on the leaves with the fertilizer or water as it promotes diseases; a drip system or hand watering below the leaves is needed.
i found this online should i maybe just mix up a batch and use this instead?
DISEASE CONTROLS
Baking Soda Spray for Blight, Leaf Spot and Mildew
A spray made from baking soda is a great all-around disease spray. It is good for treating anthracnose, tomato blight, leaf blight, leaf spots, and powdery mildew.
1 Tablespoon baking soda
2 1/2 Tablespoons vegetable oil
1 gallon water
1 teaspoon plain dishwashing soap (such as Ivory)
I tried that once, but the bad part is, you have to re-do it every time it rains. It washes off easy.
Are you sure it isn't slugs? I have something similar-looking on one of my winter squashes, and it was slugs. I changed the beer traps and some more frogs hatched out of the swimming pool, and that seemed to take care of it.