I will just post the potion bit, after ive done so, you will also be able to find gold, skill points and health, mana and all that.
What you need is Cheatengine from cheatengine.org, download this and install it.
After doing so, run

and start up your game or load a game.
Once in the game, get around 10 potions of the ones you want (infinite) and hot key the potion to your skills bar for example on skill slot 8 then alt tab and start cheat engine.
Left on top is a computer icon, click it and it will show you a process list of programs running on your pc, you'll want Divinity 2. select it and open.
Now the next step is, value type its on the lower bar in the middle and set it to: All (Byte to double) and set the top bar to: exact value.
On the value bar where it allows you to write, write 10 there or the amount of potions you have in your inventory we use 10 for example.
On the right, set it truncated, scan options 32 bit. all the otheroptions below off.
Now your ready to do your first search, and search 10. after the scan is done get back in DD2.
Use one potion you had set to the skill bar and press (f) to pauze and alt tab back to cheat engine, now search for 9 in a next scan. you will come up with fewer results on the left side. but that wont be enough.
So once again alt tab back to DD2 unpauze wait for the effect to go away and use another potion.
Quickly press (f) to pause again and alt tab back and search for 8 this time and repeat these steps until you get a total of 32 adresses on the left side.
Select them all and press the red arrow on the bottom of the adress list to add them down below.
Now sort them by type and select all of the byte ones and rightclick, change record, value and make them for example 99. then select the double adresses, and do the same, make their value 99 also.
Then enter DD2 again and use a potion and see if you done it correctly, if so you should have 99 potions of the type you searched for.
On the left side you can also freeze them to get infinite potions.
The reason I gave the potion tutorial is because its the hardest one, since it gives you back 32 values rather then 3 for health and mana etc.
For health and mana you could use the memmory region from 20000000 to 3FFFFFFF to pick up the value faster since its in that mem region, also scanning for potions is faster when doing from: 10000000 to 3FFFFFFF but its more advanced.
Feel free to give me some questions, ill gladly answer them when I can.