Absolute beginner

Hi Guys, your advice please.

Hoping to learn about putting a pc together, I bought an acer veriton M464 2008 vintage
The ad said working fine before hdd removal

On power up I have fans running, mouse lit-up and cd tray opening but nothing else
Keyboard is dead but works elsewhere
Monitor says "No signal input check video cable". Again works with other pc.
Also there are no beeps

Any ideas on how I make progress please

Many thanks

Peter Fay