The most urgent thing to buy is a faster videocard for games. That might be difficult in a laptop. The R5 M230 is advertised as a laptop card: notebookcheck says about it "Current and demanding games of 2014 will run fluently only in low resolutions and detail settings.".
If you don't find that good enough, buy extra RAM. However, don't mix different RAM's. If you now have 2*2 GB, buy 2*2 of exactly the same make and model, so you have 4 identical sticks of 2 GB, making 8 in total. Or buy 2 *4GB to replace the current sticks.
If you still find it not good enough, buy an SSD as system disk. Or a new gaming laptop or desktop.
Display Adapters --- AMD Radeon R5 M230 2GB
Intel(R) HD Graphics Family
Processors --- Intel(R) Core(TM) i3-4030U CPU @ 1.90GHz (It is written 4 times in device manager)
Installed RAM --- 4GB
Windows Edition --- 10Pro version 1709
I have games like GTA 5 and COD-Advanced Warfare but I am unable to play these without lags. I am planning to get a RAM of 8GB installed in my computer but I am not sure if it would help me to play high end games without lags. Will a 8GB + 4GB help me to play these games or it would only be a waste of money to buy RAM.

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