The transition to university is a critical young-adult milestone that demands academic, social, and personal adaptation. Challenges in this process may undermine both academic performance and psychological well-being. This study examines associations between first-year students' adjustment and well-being with self-efficacy, perceived social support from family and friends, and personality traits of extraversion and openness to experience. The study is approved by Mersin University Social Sciences Ethics Committee. The study's hypotheses are as follows: H1. T1 self-efficacy will positively predict T2 university adjustment and life satisfaction, controlling for T1. H2a. T1 perceived family support will positively predict T2 adjustment and life satisfaction, controlling for T1. H2b. T1 perceived friend support will positively predict T2 adjustment and life satisfaction, controlling for T1. H3a. Extraversion will positively predict T2 adjustment and life satisfaction, controlling for T1. H3b. Openness to experience will positively predict T2 adjustment and life satisfaction, controlling for T1. The sample will consist of first-year students at a public university in Mersin. Based on comparable studies, analyses will target about 200 participants, with at least 300 recruited at T1 to allow for attrition. Participation will be voluntary; data will be collected via paper-pencil surveys. Instruments include the Self-Efficacy Scale, Multidimensional Scale of Perceived Social Support, extraversion and openness subscales of the Big Five Inventory, the University Life Adjustment Scale, and the Satisfaction with Life Scale. Data will be gathered in two waves: (T1) the first week of the academic year (September 2025) and (T2) about two months later (November 2025). Analyses will begin with repeated-measures ANOVAs to assess changes in adjustment and well-being from T1 to T2. Correlational analyses at both waves will further explore associations among variables. Findings are expected to provide longitudinal evidence on early adaptation processes and inform development of orientation and psychosocial support programs for first-year students.