Studying Spanish on my own has allowed me to learn at my own pace and choose the materials that are best suited to my learning style. I recommend that anyone who wants to learn a language should attempt self-studying first.
Before you start, you need to have quantifiable goals. “Become fluent in French” is an abstract goal because it doesn’t define how you measure fluency. Is it by passing a proficiency test, conversing with a native speaker for at least 15 minutes, or translating a short story? Whatever goals you set, make sure you can easily say “yes” or “no” when asking yourself if you’ve achieved them. In my experience, setting a deadline for these goals also helps you accomplish them much faster.
Unless you’ve taught yourself a couple of languages already it’s best to follow the progression of an existing language course rather than creating your own. While you can look up the syllabus of college courses for that language, you might not have access to the materials and textbooks cited. Because of this, it’s more convenient to have an existing self-study program as the backbone of your learning