Fingers crossed for the job man!
My ST is my daily too so I wanted to go for incremental improvements rather than do too much at once. To start I went with a stiffer roll restrictor/rear motor mount. There are many options including Cobb, mountune, and Boomba Racing. You'll wanna read up to decide which sounds best for you. I also picked up a high flow drop-in air filter, again there are many options you really can't go wrong.
Some people will also recommend immediately switching to a set of lighter wheels and stickier rubber. I got about 32k miles out of the Potenzas and I'm still on the stock wheels and have enjoyed every minute.
Another reason these mods were great for me to start with is that I was able to do it all myself with no prior experience. Builds up the confidence to move on to bigger projects, recently headlight/fog light upgrades and pretty soon the intercooler.
I know this is all pretty basic info but I hope it helps you!