To respond to your question directly, yes, it is always preferable to eat well before considering dietary supplements. And this is especially true of beginners, since it establishes the norms by which we train throughout our careers thereafter.
The Australian Institute of Sport and its state equivalents institute a ‘no supplement’ policy for all of their under-18 athletes for this very reason. Although these athletes are elite, the importance of managing a good diet is placed above any supposed advantages that supplementation may afford. And, it should be noted, they have an impressive performance record both domestically and internationally.
The justification is simple: there is no evidence that supplementation is necessary for optimum recovery—indeed, the nutrient requirements of amateur and elite athletes, alike, are easily attained through a varied diet. A typical Western diet, for example, provides twice the amount of protein recommended for the normal population, or the maximum that can be utilised by elite strength and power athletes. And that is just the average diet! Supplementation, whilst conveniently providing the macronutrients, by its very nature—since its nutrients are refined and isolated—it does not provide all of the other nutrients essential to good health. Thus a reliance on supplements tends to encourage poorer overall nutrition.
That said, although it is not ideal, supplementation is certainly warranted when an individual has a restrictive diet, or when they otherwise find it difficult to meet their dietary requirements for any other reason. Also, there is considerable evidence to support the claims made for supplementation of certain nutrients such as l-carnitine and creatine. In such cases, whilst supplementation may provide a theoretical and measurable benefit to more advanced athletes, such benefits are unlikely to be seen by novices, since their progress is limited at a more fundamental level—restricted, for example, by the planning of their training, their skill mastery, and their tolerance to exercise volume.
So in summary, it is preferable for all athletes—beginners through to elite—to address their nutritional needs with a broad, varied diet based on whole foods. But more advanced athletes, particularly, may benefit from supplementation of particular nutrients such as l-carnitine and creatine. And although it is a sub-optimum strategy, certain athletes with special dietary requirements may also benefit from supplementation.
As a final note, it should be understood that this is not to imply that a typical diet necessarily meets all of the nutritional requirements of a beginner—poor diets are common amongst the normal population—but rather that with careful planning and attention, a broad and varied diet can easily meet those needs. And it should go without saying that an understanding of dietary planning is an essential skill for any beginner to learn.
I hope that offers you a different perspective on the issue.