How to create an object by dimensions I have taught myself a few basic things in Blender using Youtube video tutorials but still am &quot;all thumbs&quot; when trying to work out how to create an object (for MSFS2020) consisting of a dock used by float planes.

I have created a motor vehicle tyre-like object but not added a material using the TORUS mesh object (very easy).
I have downloaded and imported some 3D objects to try to work out how it is done but still I am scratching my head.

It would be great if I could watch a video tutorial which someone can point me to which shows how to create a similar looking model (doesn't have to be a dock but similar in shape to a dock) or give me some easily understood ideas.
I have included part of an image showing the type of object I would like to create in Render.
An example would be to create a 'cube' which like a regular plank of wood. I see that I can drag the vertices of a cube to represent a plant of wood but how do you ensure all sides are parallel to each other ie that the plank is as think one end as the other. I am thinking for this object all that is required is a number of 'planks of timber' placed in correct places or joined together.
Thanks
[added later]
I just found a youtube video tutorial how to make a wood plank but still nee to know how to create to a particular dimension eg 3.6 metres long, 200mm wide, 50mm think. Also I will have to create a number of different 'plank's and then duplicate some and attach all the parts into the dock. Youtube video
The dock should be rather easy to make.

Add &gt; Mesh &gt; Cube and enter the plank dimensions (3600x200x50)
Then go Apply &gt; Scale
Now add the Array modifier (to duplicate your planks)
Use the same principles to create the rails and the bottom floating part

Planks made using Array modifier





Bottom part




Final model