I've been using the machine for two years. It's normal that you have to heat it up for a few minutes to get a good espresso. I switch it on and after a few minutes I let out an espresso cup of water so that the portafilter comes into contact with hot water and the stale tap water is gone. After 5-10 minutes, remove the portafilter and rinse again with hot water from the machine in case there is any residue on the brew head.
For a simple espresso, the machine is ready after 5 minutes or less (control light), but to ensure that the portafilter is also nice and hot, it takes longer. For the perfect espresso, everything must be hot and the colour should be nut-brown. Ideally, it should run down thinly like two "mouse tails".
That's why a good grinder is also important.

Thank you!

even longer than 10 minutes, because the plunger should be nice and hot for a perfect espresso!