If we take as our example the lives of the saints who were ordained and/or members of religious orders, there's no cookie-cutter approach to vocations. Some exhibited great piety as children and entered consecrated life in their youth. Others were dissolute until a late conversion propelled them directly into their mission. The road you and I take to fulfilling our baptismal call will follow its own rhythms. However long it takes and whatever we bring to it, we trust God will use us for divine purposes.
With that in mind, here are some practical criteria to consider in your discernment. If you're a lifelong practicing Catholic who "presided" at Necco-wafer Masses in childhood or wore rosary beads dangling from your skirt button in imitation of the sisters at school, the seeds of vocation may have been expressing themselves in you playfully for a long time. After a few decades of absorbing sacraments and deepening virtuous practices, it may seem that the call to consecrated or ordained life is new when it's really as old as your baptism.
I generally caution new Catholics, however, not to leap directly from the Easter Rites of Initiation into a deeper form of commitment for at least a year, and certainly not without a dedicated spiritual director to walk them through the discernment process.
Which brings us to the next point: Discernment is never a solitary pursuit. The church is the umpire when it comes to vocations. Until a church official deems it a strike or a foul, so to speak, it's not on the board. Along with spiritual direction, periods of retreat and pastoral counsel accompany the average journey into a church vocation.
Both seminaries and religious communities require a period of testing and evaluation before they admit candidates. The ensuing process of academic study and/or community formation are themselves additional phases of discernment on both sides, properly understood. Even short discernment processes, therefore, are technically long ones. And there are no losers in this process, because whatever the verdict, what you learn about the nature of your call is not wasted.
• The Art of Discernment: Making Good Decisions in Your World of Choices by Stefan Kiechle, S.J. (Ave Maria Press, 2005)
• The Meaning of Vocation by Pope John Paul II (Scepter, 1999)
• Still Called By Name: Why I Love Being a Priest by Dominic Grassi (Loyola Press, 2003)