Ants & Rocks/clay! How can I get the perfect plot?

Hello! So I decided that today would be the day that I started digging up the grass and making preparing the soil for planting! (Completely new gardener, vegetables)

Within seconds of digging up the first layer of grass I was swarmed with thousands of ants... I had ant killed nearby as we get them a lot on the patio (Next to where I'm digging), so I used a little and in 5 minutes they all went. So I continued to dig and add ant killer as I went along. So now I have my first row complete, around 0.6M wide and 2M+ long. 

My main concern is the ants. Will they affect any plants that I put in? Mainly planning strawberry plants that have been growing in pots for now, cauliflower that has also been growing in pots and what I'm waiting on coming; Carrots, Sprint Onion, and Herb Mint.  

Now my second annoyance should I say... As I was digging there was A LOT of rocks, big and small, if I got some out, there would be more and more... I've seen some guides to just digging the soil + rocks up and putting them in a milk tray to filter the rocks, then re-adding the soil, I'm fine with doing that but it will take a long time due to the fact that ants are not my cup of tea, so I would be running away every 2 minutes when finding another herd of ants... Is there any other way? The one thing I have thought of is just digging half a meter down and them filling it all in with compost, if that's cheap enough... Then of cause I will get my compost bin setup soon to keep a refreshing amount + using for potted plants etc... So that's the second problem.

Now to the last problem. Clay soil! So in my area it’s pretty much Clay Soil (Not sure if there is a specific name for it or not). Which I guess is good for some plants and bad for others? Referring back to my idea with the compost then I think I wouldn't have a problem with it, apart from the endless digging to get the right dept. Is there a way to treat clay soil so eventually I'll have nice soil to plant my veggies in? 

It’s a little bit long winded for which I am sorry for, but I'm really new to the garden and my knowledge is a little scarce on plants and landscaping. I'm only 16... 

Some more information that may be needed - 

I live in England, East Midlands. In our garden we have a lot of trees but no plants, so I couldn't say if any plants grow well here. Our neighbour that plants a lot of veggies just uses compost (I think from taking a peek), and has had conversations with my mother about the clay soil and how it’s a shame. Adding onto these conversations, we are the higher part of the side of the street, as the houses build on the lower side were build first, so all of the 'crap' was moved over to our side before our houses were built onto this matter. 

That pretty much sums it up! I would be most appreciative of everyone's advice and opinions. Thank you for reading.