Hey @Clacker
Your description is indeed a little confusing
SVGs are coded, or if you want so vector-based images. on the contrary there are pixel-based images like PNG, JPG, TIFF and so on. If you convert a SVG (vectors) to a pixel-based image (f.e. PNG) you will loose the advantages of vectors (scalability = sharpness in all sizes etc.)
So if you want to edit a SVG, you should use an app like Adobe Illustrator. Or anything else, that can handle vectors.
Affinity Designer is available for little money. With it all illustrations can 1. be created and 2. export, 3. convert in almost all formats: tif, eps, png, jpg etc. As described above @benfluri, however, you lose the advantages of vector-based files.