Importing an SVG or TIFF file into Sketchup?

raster files as e.g. JPEG, PNG, BMP or TIFF can be imported as an entity in the model via “File > Import…” by using the option “Use as Image”.

https://help.sketchup.com/images/fg114_1.png

Manually digitizing the raster data by sketching over the image will lead to extrudable vectors.

Vector data of SVGs cannot be imported natively by SU but you can convert them to the DWG/DXF format (= industry standard for 2D CAD data) by using free Inkscape.

more info at:
• SketchUp Help Center : Importing and Exporting Image Files