Make sure all tools are clean
1 : 2 ratio is a good place to start for a lot of coffees. 18g of coffee = 36g of espresso
For lighter roasts / coffee higher in acidity you can try 1:2.25 Brew Ratio.
1. Grind 18g into the portafilter
2. Push down with the tamper to evenly compress the coffee
3. Lock the porterfilter in place into the machine and place a cup/s underneath
4. Start the extraction, stop when you reach the desired output. This should be 25-30 seconds
This is what works for us, of course brewing is subjective and you can make your coffee however you like!