The tutorial you are following is full of bad practices! My eyes are hurting just looking at it.
I am even more surprised that @al.whatmough who is directly involved in Fusion 360 development thinks it's a great tutorial.
1. The tutorial does not follow Fusion 360 R.U.L.E.#1 and with this simple design there is no need to turn a body into a component. He should have started with making a component and ensure it's activated.
2. He does not fully constrain and dimension his sketches, which from a mechanical engineering standpoint is totally unacceptable.
3. Copy/pasting a sketch to create identical geometry without parametrically linking it to the original sketch is also a bad idea. In fact he could have easily created all of the dovetail slots and sliders from a single sketch. Copying sketches that are not fully constrained and then pasting them int o a new sketch and not properly constraining them there either is unforgivable.
4. When he creates the sketch for the handle he states he wants to create tangential lines but then fails to notice that bot the top and bottom line joined to the circle with a coincident constraint but not also an tangential constraint.
5. Later on he states that the circus need tube trimmed, which is entirely unnecessary.
6. the spline he's drawing has way to many points for that simple geometry.
7. By ny means, components should be assembled no all at the end of the design, but as you go.
8. Applying chamfers and fillet in sketches is a solid modeling no-no.
9. Creating a modeled thread on an already chamfered cylinder will not create the proper thread start and will throw you for a loop if you want to 3D print a design. You'll have to apply the chamfer after the applying the thread.
10. He grounds the base before starting the assembly a the end o the video. A component can and should grounded right at the point of creation so very early on in the timeline. Grounding ties the component origin and the design origin together, so a component can be grounded without any geometry it!
While @lucasproko's tips might make your design functional, when going through the timeline I see potential for a number of improvements.If you're interested I can create a screencast of how I'd build this piece.