The US Foreign Service Institute places Spanish among the languages closest to English. It estimates 24 to 30 weeks of full-time training, about 600 to 750 class hours, for its students to reach professional working proficiency (FSI language training). Most adults learn part-time, so think in months and years rather than weeks.
A good first milestone comes much sooner: follow a short A1 story without translating every line, introduce yourself, order a coffee and ask for directions. Those are the first three units of the Spanish path.