How to upgrade a normal desktop pc to a gaming pc? (specs below)?

System model- Acer Aspire XC -605
processor- intel core i3-4130 cpu @ 3.40GHz 2 cores, 4 logical pro…
RAM- 4 gig

basically, i have very limited PC knowledge and would love some help in upgrading my desktop to run games well (I like minecraft modpacks like FTB infinity but it often has some insane framerate drops) any info into what i should be looking for and how much it'd cost would be incredibly helpful.

Better graphics card, RAM, processor and cooling system.

If you have the money then you may want to upgrade your graphics card (GPU) and your RAM. I suggest upgrading to a gaming gpu like NVIDIA. Upgrade your ram to 8gb or more (16gb is beast). All that would probably cost you $1100 - $2000 depending on which Graphics card you buy and how much ram you are upgrading to. Also upgrade your core i3 processor to a core i7. Other than that i suggest buying a new gaming pc as it is much easier or you could get a friend to build you a pc for much cheaper