IFC import is not so scary as it looks from the first sight.
Let me try to guide you:
When you open IFC Translators window you see SIX fields.
1. Model Filter - here you can choose what you want to import from IFC file. For example everything, or only walls or MEP elements or only load bearing elements - i.e. choose by structural function, by IFC domain (all, structural, MEP) or just choose by type (ifcWall, ifcBeam etc.)
2. Type mapping. IFC - it's some sort of script, written by "IFC language" and remains a little bit HTML. So, in that "language" exist types - ifcWall, ifcBeam, ifcSlab and after following descriptions - like coordinates, shape and properties. Type mapping letting you to choose which IFC element type will be converted into which ArchiCAD Classification. So, ifcWall will be Wall, ifcSlab - Slab. You can use standard ArchiCAD classification and default pre-set. You don't really need to create custom classification that ifcWall would have in ArchiCAD class ifcWall too. It will not give you any difference.
3. Property mapping - you can choose which IFC properties will be mapped to ArchiCAD properties. If mapping table remains empty - you still are getting ALL IFC properties in ArchiCAD, that was included into file. You also can schedule IFC properties in ArchiCAD. The only place where IFC properties are not available - graphic overrides. So, if it is important for you to use IFC properties in graphic overrides - then you can prepare conversion table (and create custom ArchiCAD properties). Otherwise - don't waste your time.
4. Geometry conversion. Here you can choose - convert elements into library parts, morphs, match construction elements (that slab would be as a slab and walls as walls). It depends on how complex original model is. Sometimes walls are converted into morphs anyway, even if set match construction elements, because originally wall do not have simple geometry.
5. Layer conversion. I hope this is clear. When I import IFC files - I always match to my layering system, to keep file well organised.
6. Material and Surface Conversion. You can match IFC materials with ArchiCAD building materials and surface. I recommend to use it, if you want to have nice looking model. Otherwise you can get ugly vivid colour elements - like cyan, grey, red, blue...
In all six cases you can create your own pre-sets or modify existing.