The three options I have are
Mother Earth Groundswell
Or Fox Farm Ocean Forest, or Happy Frog,
Is there a different variety of Fox Farms that is better for my autos?
I only want to buy ONE BAG, and was wondering which of these three options will work best?
I get overwhelmed by this type of thing, so a simple answer would be great. Thanks everyone! 
I would go with Happy Frog. Im not familiar with Mother Earth. Ocean Forest is too hot for autos.
Midwest Guy is spot on. Ocean Forest will burn and stunt seedlings. It’s better used when mixed with Happy Frog or Strawberry Fields, or layered underneath.
I’ve never used Mother Earth. However I’ve had success with both Happy Frog and Ocean Forest growing autos.
I’ve never understood why Ocean Forest has a reputation for being overly hot? Ive grown wonderful autos in it.
What I have noticed is when using with Happy Frog or Ocean Forest there little need to feed your plants during the first few weeks of veg. The soil contains amply nutrients right out of the bag. If you feel the need to feed during veg, perhaps feed your plants 1/2 strength.
Both are exceptional soils IMO.
I use the Happy and Ocean. Shame those Foxfarms soils are so expensive online. I get the Happy for $13.47 a bag and the Ocean for $14.99 a bag at my grow store. Any of the options you listed would work but lean on the folks that grow autos advice. I just grow photos.
Happy frog would be my soil of choice. All I grow is autoflowers and Happy frog is my go-to soil. With 30 days worth of pre-charged and nutrients already included in the soil
Mother Earth’s Groundswell is a very light amended soil enough for about 20 days of nutrients. It’s a good soil.
Fox farm ocean is another good soil but I agree with everyone above it can be way too hot for some plants.
Happy frog for the win
I use happy frog and for the most part had great success. Its not too hot nutrient wise so you can just plant your seed and it will be good for about 3 or 4 weeks before it would need to be fed. Though, prepare ahead of time for fungus gnats. They really seem to love that soil. Add beneficial predators like nematodes sf, or mosquito dunks.
I’ve used HF and Groundswell. I prefer the groundswell, but it’s strictly personal preference. They’re both good soils.
I went with happy frog. I ordered 2 cubic feet of happy frog online, but i have 3/4 of a 1 cubic foot bag of a store bought organic soil called “Whitney Farms Organic Potting Soil.”
