Lens for old 35mm Nikon SLR

Hello
I am very new to photography and have inherited a Nikon SLR 35mm camera from my dad, and need some help with what lens to use. I don't need any zoom, I simply want a very slim lens to use as the current one is very bulky (8cm long or something) and I know that I just won't use it as much.

On every website I have visited, the lens seem very advanced with zoom, automatic focus etc. I need something of good quality but just rather basic in its credentials. I essentially just want to look through the viewfinder, focus the lens and click.

Surely this shouldn't be too much to ask?! I would be very grateful for any help or advice given.

Thanks
Tessa