Here's some tips to build cheap gaming pc. I would suggest some parts you need to buy for a tight budget using "Shopee"

Motherboard: MSI A320M PRO-E Socket AM4 - P2,699 (Shopee)
Processor: AMD Ryzen 3 2200G Socket AM4 - P5,600 (Shopee)
Ram: Kingston HyperX FURY DDR4 8GB - P1,680 (Shopee)
Storage: Kingston SSD A400 240GB - P1,695 (Shopee)
PSU: FSP HV Pro 550 Watts Power Supply 80+ Certified - P2,099 (Shopee)
Case: Rakk Anyag Gaming Case Black - P1,000 (Shopee)
Mouse + Keyboard: INPLAY STX200 Rainbow LED - P240 - (Shopee)

A total of P15,013 and above because of the shipping fee. You only have to do is to buy some chassis fans to make a good airflow inside your rig. You can buy separate fan of maybe 3pcs (P120 each) in shopee. In Power Supply, I suggest to do not save or not to buy a cheap power supply if you don't want to regret in the end. I will recommend the power supply that has a 80+ certificate because it has a good efficiency to fulfill power in your computer.

It can play a games like:
GTA V (normal setting)
PUBG (Medium Setting)
Dota 2 (Medium Setting)
Valorant (Low-Medium Setting)
and other game that fit into this build.

This build can game without GPU because the AMD Ryzen 3 2200G has a built-in iGPU Radeon Vega 8 Graphics, It takes 2GB space in your RAM to make it as VRAM that why you can have a display and play Medium setting games without GPU.

That's all! I hope you learned something from the tips I shared with you! Have a nice day! Good luck!