Coffee

I have an espresso machine, some shitty AI generated brand my mom bought me from Amazon (chefman it's called, and it's not actually all that shitty I don't think). Anyways every time I go to make a mocha or some other kind of flavored latte, I have no idea what I'm doing. I usually do two shots of espresso, then fill my mug about halfway or less with milk and flavor (choccy chips or one of the syrups I have), steam it for uhh like 60 to 90 seconds, then add the espresso in.

I find my lattes... or cappuccinos? I'm not even sure of what the end product is when I make stuff. Anyways I find them ok, but not as good as products from actual cafes. For example, starbucks mochas are better than my homemade ones, and the mochas at this random ass cafe in the local hospital are also, in my opinion, better than mine, though it's been a while since I had either. I don't know what I'm doing wrong, mostly because I don't know what I'm even doing. How much milk should I be using? How much flavorings, how much sweeteners, if any, do I pour the espresso shots into the cup after I steam the milk or do I pour the steamed milk over the espresso? How long do I steam it for? Is my machine actually shitty like I earlier described or am I being rude to my mother?

In short, how the hell do I get professional, cafe level mochas at home with my machine?

Edit: TIL I know nothing about espresso making...

Edit2: Ok here's my exact process.

1. I get the bag/can-thing of preground espresso-designated coffee grounds I have in a cabinet.
2. I scoop some out, and fill the designated 2-shot portafilter my machine came with to the very tip of the fill line (usually leaves the portafilter nearly entirely full). Then I tamp, and then put the grounds away. The exact amount is unknown to me, and I don't measure particularly well.
3. I put the portafilter in the machine, then press the 2 shot button to serve the shots into a ramekin or some small dish large enough to temporarily hold the espresso. The machine has time settings for 2 shot servings, it pours liquid for some adjustable period of time but I left it on default. I don't recall what it is but I believe it's around 20 seconds?
4. After the espresso is poured, I pour some milk into my designated espresso mug that I will drink out of once everything is done. I do not measure the milk; I just pour until I feel like I have enough milk. I also usually add some flavorings; syrups or chocolate chips, usually.
5. I turn the machine's frothing mode on, wait for it to preheat (there's a preheating indicator), twist the knob that allegedly controls the steaming wand to max, and froth the milk for about 60 to 90 seconds, or until I can visibly see a layer of foam. The dial for the steamer is continuous, it's not a binary on-off or discrete off-min-mid-max thing, but I don't actually know what it controls besides on and off.
6. Once the milk is frothed, I pour the espresso into the mug, stir, and drink.

Apparently I ought to be measuring the grounds before putting them into the portafilter, and measuring the espresso as it pours, though I have no control over how much is poured beyond the time the machine runs for. I don't know, I'm a scrub at this and all my espresso gear was gifted to me over the years, including the grounds. I apologize for being a heathen, please educate me on this art. I have no other resources besides the internet (which is 90% AI) and Youtube I guess.