I can somewhat relate to you, Mihn, and Taylor. Before I became a member of a Reformed church, I have been given opportunities to teach in the singles ministry at a non-denominational mega church that I was once a part of.
Having skills in teaching and training (as I was an Instructional Designer and Trainer by profession), I think that was what gave way for the opportunity to teach in ministry, on top of my desire for deeper studies of the Scripture.
Around that time, I was "reforming" while also teaching in the ministry (I thank the Lord for not allowing me to teach when I was in my cage-stage, but I'm sure there were hints of it). This was a struggle because the foundational doctrines that I have learned from the Reformed tradition is in contradiction with most of what the mega church teach.
For a time, I tried looking for Reformed churches while still teaching on Fridays at that mega church and by God's grace, He led me to a confessional reformed church. In this journey, though I have a desire to go into ministry, I knew there it's not as easy as that.
Be part of and commit to a local church. Just a background, I am currently finishing a degree on Theological Studies and this happened even before I became part of our local church and it is actually through our church that I was introduced to the school (Miami International Seminary). While I do learn a lot from my studies, it is in the context of the local church and guidance of our elders that I am able to maximize the things I'm learning at the same time being mentored accordingly being prepared for ministry.
While I am way far from church plant or even ordination, but because I was able to express my desire and asked to be mentored, our pastor has recommended that I apply for internship at our church and for sure will be learning a lot more from this experience. I see that you're a part of Free Presbyterian Church in North America according to your profile, your elders should be able to confirm and guide you and pray for and with you.
My experience is unique and what you'll go through would probably be different. Continue to pray for guidance and wisdom at the same time be guided by your elders. You don't want to be going through seminary then end up not really wanting to be in ministry. A lot of people have already wanted to go into ministry because of "skills" or because they do not want the situation they are in. Don't get me wrong, of course skills are needed, but solely because one thinks he has the gift that he should go to ministry, is I think not a wise reason for going into it.
My girlfriend's uncle who is also a pastor, when he knew of my desire to go into ministry has asked me a very wise question that I will never forget. He asked, "are you willing to die for the sheep?" Since then, I have viewed ministry in a whole new and serious level.
(At the same time, he asked my girlfriend if she is willing to fully support me in the ministry-we're still together a year after that so I guess it's a yes haha)
There are a lot of pastors here who have decades of experience and can give you better advice on ministry and preparation compared to me who is just about to really start the "kindergarten" of ministry. But I'm with Robert's advice: to pray, pray, pray.
Read a lot, learn a lot. And get your books from heritagebooks.org, I get almost all my books from them, including Witsuis' The Economy of the Covenants and its outline.
And Vos, get Vos' ST! One of the greatest advice Rev. Lane has given to me and probably to most of the PB members (Still working through it though

).