Question I have a problem with my pre-built pc

[42k_Teo]

Ok so ill try to explain the problem so i just got my brand new pc its a pre built one and i love it i got the right specs and everything so i went to boot up the pc first i plug everything in HDMI cable to the monitor i blug in the power cord and btw this pc dose not have an OS so i boot it up and the rgb lights on the case the graphics card everything lights up! But nothing shows on screen my monitor just turn off i guess it just wont display a picture it dosent even let me like hit the BIOS key nothing idk whats going on and i am new so idk what i am doing

 

[Nemesia]

Hi 42k_Teo.

Can you please list the entire specs of that system including the PSU brand and model?