This is how I was able to build my 10ft long desk, completed with a full metal frame and 2 pieces of MDF (Medium-density fibreboard).

Supplies

Wood 3/4th in. x 23 1/2 in. x 120 in.(for the top)
Metal Beams 1 5/8th in. x 1 5/8th in. x 120 in. (for the framing)
Buzz Saw (for cutting the metal into correct sizes)
Metal Grinding Machine (for grinding off the sharp edges of the cut metal)
Bolts
Spring Nuts
Self-Tapping Screw
Drill
*Optional*

120 Grit Sand Paper (to get rid of all of the impurities on the metal to spray paint)
Paint Thinner (to clean off the metal)
Spray Paint

Step 1: Creating an 3D Model

The first step I did to create the desk I have today was to create a simple 3D model. The model would help me see how it looked before I created it to change and perfect everything I wanted. The model was created from tinkercad, a free online 3D model website that's easy to create models.

(This is the link to the tinkercad model to view the entire 3D model)

https://www.tinkercad.com/things/kGIxr0nsoLz

Step 2: Cutting, Grinding, and Painting

Because the metal beams that I bought came in 10ft long pieces, I had to mark them using a measuring tape and a sharpie. Then I cut them all to pieces using a buzz saw to cut the beams to size and then a grinding machine to grind around where I cut the metal because the buzz saw leaves sharp edges on the metal. After cutting all of the beams to size, I used 120 grit sand paper to light go around the entirety of the beam to get off all of the impurities in the metal or dust. After using the sand paper I wiped it all off with paint thinner to make sure there's no dust on metal shavings on the beams, then I was ready to paint. For the beams I used a dark navy blue and making sure to give it enough time to fully dry. (looks brighter in the image to to camera contrast)

Step 3: Putting Everything Together

After letting the paint to dry I used the 3D model I made before to have an outline of what pieces go where. After setting everything up I used spring nuts and bolts to bolt everything together into the frame. When everything was bolted together I put the two pieces of wood on top of the frame, then screwed them into the wood and metal.