Best bet on RAM is to buy memory certified to work with your model.  Kingston, Crucial and others offer tested memory.  The "don't buy" is both ends of the spectrum:  value RAM and high-end gaming RAM, neither likely to work. Remove the base cover to check on the drive that's installed.  A 2280 drive will be 80 mm long;  2230 is under half the length.  In general, 2230 drives are smaller capacity (generally no larger than 1T in size, but more commonly smaller).  You may also need a mounting bracket and screw for a second drive, which likely won't be in the system.  Any drive you buy should have a spec sheet with the size indicated. You use the Optimus control panel to select the GPU you want on a per application basis.   If you're going to be using photoshop and lightroom extensively, I'd rethink this purchase -- while you can no doubt run the applications, you'll need a sense of patience, since the hardware is decidedly entry level for those applications.  Even with the nVidia GPU and added RAM, it's not going to be a stellar performer.  And given the age of the system, it it's not coming with a new battery, expect that to be needed within the year as well.    
I've ordered a refurbished G3 15 3500 arriving Monday. It has an i5 10300h processor and  the GeForce gtx1650 to graphicsbeoyh a 500 GB NVMe. I want to add more ram and add a second SSD envy Me. It says memory speed is 2933 GHZ. Can I add an 8 GB 3200 GHZ module which will run at 2933, or do I need 2933 or slower? Secondly the manual states that it will take two m.2 envy me drives but one has to be a 2230, and one a 2280, for both to work. How do I find out if the one already in is a 2230 or 2280, and how do I find which drives on Amazon are 2330 and 2280 as it's not stated.  Thirdly, I need the GFX card for Photoshop/lightroom, so how do I ensure that card is running and not the other card. I'll probably be adding my Acer 27" monitor as well. What do you suggest for all my issues?
G3 15 3500 upgrade.