Question newly built pc working at first but now i only see a black screen

[dumb man]

Alright so what happened was i built my first pc i started it it worked gpu lights went on motherboard lights went on fans started to spin so i was really happy then i tried to install windows with an flash drive but when i got to the actual installing part it didn't work. So i tried it with another flash drive so i put it in my pc turned it on and every fan started spinning gpu lights went on but my motherboard only gave a flash and the lights then stayed off and i could only see a black screen on the monitor. I am really scared i broke something but i don't know what i'm really sorry for the bad english but it is really late.

Edit: Is it possible that the motherboard got bricked or something i read something about bricking somewhere

 

[rgd1101]

full system spec? include make and model of the psu

 

[dumb man]

full system spec? include make and model of the psu

specs are
Gigabyte b550 elite
Ryzen 5 5600X
G.Skill DDR4 Aegis 16gb 3200Mhz
Thermaltake TR2 S 700W
Intel 660p 512GB
MSI Geforce RTX3070 Gaming X Trio
Cooler Master MasterBox MB511

That's about it i am going to upgrade my storage but this will do for the first month. I am sorry but i don't know what a psu model is i am new to this.