Throw it all in a blender or nutribullet
Add water and sugar
Heat

Sautee onions/garlic, add drained can of tomatoes, add spices. Cook until desired consistency is contained. Is it going to be the best tomato sauce? No, but it'll be passable.

Ideally you'd start by cooking a little bacon or similar to render out some fat. If you don' t have any then just put a little oil in a saucepan. Lightly brown the onions and bacon. Add the tomatoes. Cook at low heat until the tomatoes get soft and the flavors come together. Taste and season with salt and pepper.

Mince and dice the onions, then sweat on medium-high heat until they just start to carmelize. Add garlic and briefly sweat for 30 seconds - do NOT let the garlic burn. Add oregano, basil, and perhaps a little rosemary. Stir in the tomatoes and bring to a boil. Add a little sugar to taste, then some salt and pepper. Reduce to a simmer and cook covered for 20 minutes. Remove cover and simmer an additional 30-45 minutes until the sauce thickens and reduces to your liking.

Good luck. Keep at it until you find a recipe you like.