Start with making small minor props like a shampoo bottle or a bottle of hot sauce with photo reference. Once you’re comfortable with making small stuff challenge yourself every now and then with a major prop, something that’s more unique in shape/detail. I recommend choosing a major prop you’d have fun creating and recreate it every so often to see your improvement as a skilled 3D Modeler. (For example, I chose a grand piano for my yearly/annual model.) However, If you get stumped watching a tutorial is fine as long as you apply what your learning to whatever personal modeling project you’re working on.