3d Scan to Fusion 360 A-Z to teach me

I need someone who can live show me/teach me how to convert a 3d point cloud scan (from Creality Scan) into a solid parametric object in Fusions360.

I have aligned and merged the object into a single object and saved it in .asci .obj and .stl format.

its an organic item and so there is around 1.5million triangles.

i need to design a tight fitting base for the object with complex geomtery and so its important there is not realistic loss of fidelity 0.1mm or so.

i would like to import and use this in Fusion360 but it is simply too large i feel. i have tried reducing but its imperative that the geometry isn't too badly affected.

the file is 85mb so cannot upload at posting the project.