All good advice from Peter. Get some practice beans before committing to the good stuff. Get your technique down first.

A hot, primed boiler is best to work with. Never pull shots from a cold start. It'll damage your boiler and you won't have the right temp anyways.

A good grinder is key. You'll need to play w/ grind setting, tamper force, and pull timing to get the shot you want. A lot of that is feel (and taste). I started from the Golden Rule (20 to 25 seconds) for the timing. I find that more than 25 seconds means the pull is too bitter, grind is too fine (leading to a longer time), or the tamp is too hard. I have bought some beans that instructed me to a pull of 28 seconds but that's not common.

If you get some beans from a local roaster (or online) ask their recommendation for the time. That should give you a sense.

Happy drinking.

Another tip. It helps to warm up your demitasse cups before pulling the shot into them. You can use the water from the prime cycle too. By preheating the cups, you ensure that you keep the shot warm, rather than letting that heat warm up the cup. Makes a big diff. I learned when I went to Barefoot. They give you a free shot w/ your bean order. I asked for it to go and you would've thought I shot somebody w/ a gun. You never order that to go. You drink it in a piping hot, real cup, just like the Italians.