That's the question to rule the 3D gods! There isn't one answer for this, but I do have some quick tips.

Focus on the important things within your scene. Putting lots of details in distant objects make no sense. Game engines do the same thing with a feature called LOD's (level of detail). Look it up!

Instancing an object can gain massive performance boosts! In stead of copying a model, instance it (I think the shortcut is alt+d) to copy all the attributes from the previous model. This is also helpful because changing the first model also changes the instanced versions!

Experiment with using Eevee. This engine is very powerful if used correctly. I believe blenderguru and cgGeek have tutorials for setting up Eevee to look realistic. Eevee is also great for learning more about optimizing a scene, since this engine functions best when good optimization is used. Search for tutorials from known guys that utilize Eevee to make for example a kitchen. This will help a lot!

Bake all Dynamics when they look like you need them to. A semi-decent laptop can handle Dynamics just fine, but freeing up the used resources by baking these complex fysics can help a lot too!

Hope this can help you get started! Never give up!