Upper left corner, magnifying glass icon, select the game as the process
In the upper right, put a value to search for in the box
Click "First scan"
Cheat engine will scan the ENTIRE memory of the game and show EVERY instance of the value you searched for. Like, insanely powerful. This is exactly why basic anti-cheat is a thing, to prevent this kind of snooping. The problem is that there are way too many values to know which one we want to change.
Take some kind of action in game that makes a predictable change to the value you want to mess with
Change the value in cheat engine and click "Next scan"
Now it will only show values that started as the first scan and became the second scan.
Repeat step 6 until there's only 1 value left (might still be a few, can select all, but YMMV)
Right click, add to list
Change the value to whatever you want. You can also freeze it, which prevents the game from changing it.
As long as you're searching for an integer less than ~2 billion, you shouldn't have to mess with the other options. If it's anything more complicated, you need some basic programming knowledge, or you might be out of luck. Some values can't be messed with this way, but I don't know cheat engine much more than this.