irregular shapes alignment

[yann.vautrin]

Dear All,
First of all, thank you to Autodesk for such a fantastic tool !
New to Fusion360, I have extensive experience in vector 2D design, and really looking forward to master 3D!
I am lost on my first 3D project about bodies alignment for irregular shapes...
How can I align the bodies (see screenshot) center based? Shall I create a new body and use it as an alignment reference?
Thank you for your appreciated help!

[davebYYPCU]

Without your file, and the timeline has no helpful info, 

Big step to 3d modelling, but you are already working too hard with 2d workflows, (scale move, move , ….)

Better to build them in place, from the start.

You model appears symmetric in the vertical plane, so explaining my timeline, 

I Patch lofted half, with two profiles and 3 rails. 

thickened, and guessed the size to be about right, 

Mirrored and combined to one body.

Created a sketch with stripes, and extrude cut the voids.

Many ways to get stuff done

Might help....

[yann.vautrin]

Thanks for your reply, as I said, I am new to 3D design, so still have the "bad" habits of 2D!
Here is my file : https://a360.co/2I3cO61
The whole idea id to model a 3D shark toy before I cut it on my CNC !
Thanks for your help!