Days 1 to 7
One core lesson a day, about thirty minutes, or split it into two shorter sessions if that fits your day better. Speak into the microphone at every prompt. For this first week, do not look anything up and do not translate in your head; the method needs a week of you trusting it before it starts to work. On day seven, ask yourself three questions: Did I look forward to today's lesson or force it? Can I still use what I learned on day one? Have I actually spoken out loud this week? If the answers are bad, switch to your alternate program now rather than in month two.
Weeks 2 to 4
A core lesson on three days a week and the short focused activities (pronunciation, listening, vocabulary) on the others. Five or six sessions a week. If a pattern still makes no sense after two tries, look it up somewhere else; plenty of people do, and it does not break the method. Missing one day is fine. Never miss two in a row.
Weeks 5 to 8
Keep the rhythm and add the stories and phrasebook material once a week; that is where the sentences start sounding like something a person would say. Start a two-minute habit: at the end of each day, say what you did today, out loud, in the language, badly. It gets less bad.
Weeks 9 to 12
Finish the first set of units at four or five sessions a week. Rosetta Stone builds strong intuition and gives you no explanations, so by now you will know which of those you need more of. Before day 90, have one real conversation with a person: a tutor, a language exchange partner, or a friend who speaks it. That conversation is the point of the first 90 days.
Give it the full 90 before you judge it. The difference between people who learn a language and people who don't is rarely the program. It is whether they kept going after the first month.