Basically I am building a fixie. I have all the parts except for the bottom brackets, the headset and the stem. I didn't buy them because I am not sure about the size and dimensions I need to get.
The frame is an old francesco moser frame.

The diameter of the bottom bracket is 40mm and the length is 70mm. As you can see on the attached picture it also has some threading on both sides.
The diameter of the fork tube is 25mm, and the diameter of the tube it goes into is 33mm.
I am sorry about my terminology but I am new to all this.
I would be very grateful if you could recommend which parts I should buy.

could be italian or english threaded BB. IDK. you might want to look at this guys webpage... he refurbished a vintage moser frame that might be similar to yours, with modern components.

Your bottom bracket shell appears to be Italian threaded (36 mm x24tpi) but the exact type and design of bottom bracket you need will depend on the crank you have. Your fork is a 1" (25.4 mm) and you need a 1" threaded headset and a 1" "quill" stem of the proper length and configuration.

However, based on your questions, it seems to me what you really need is a reliable bike shop or access to a bike co-op to provide the exact items you need and the ability to install them properly.

Headset according to the bore in the headtube and the diameter of the fork crown race (measure?)

BB is threaded , what thread pattern ? Moser was an Italian .. BB choice depends on your crank choice, not independent of it.


I'd highly suggest finding a Professional Bike shop since you are completely new to this . new to mechanics and getting a fixie seems Paired a Lot from reading here.

have Shop. say Make It so.

& dont forget that front Brake.

My crankset is [h=1]BLB Pista Vera Track Crankset - Polished[/h]Fluted crankarms & flower shaped chainring
Alloy 165mm arms
JIS square taper (113 BB)
1/8 130 BCD chainring
46T only

I am not quite sure about the threading tho. All i know is that its parallel to the rim and extends about 3cm inside.
Unfortunately the closes reliable bike shop is over an hour drive so I am trying to get all the components online.

The crank takes a common JIS square taper bottom bracket with a 113 mm, spindle but the threading for the cups is still a guess. Most likely it's Italian but that's not certain.

You will need the proper tools to install it and these vary depending on whether it's a cup-and-cone or a cartridge design. Also, the headset requires special tools and knowledge to install and you need to be sure whether it ISO (most likely) or JIS.

That one hour drive to the bike shop will be money and time well spent. Getting components on-line requires you know what you need and how to install it. It seems you lack both. I don't want to sound dismissive but you need professional assistance with this project.