A call to priesthood isn’t like a light turning, and “road to Damascus” experiences like that of St Paul tend to be in short supply these days! Granted, that’s not to say that sudden conversion / call moments don’t happen although the tend to be a lot less dramatic than St Paul’s. For most people, as someone accurately (but unhelpfully) put it to me: “if you can describe a call, you haven’t got one”. At the same time, motivations, expectations and desires all play a part in helping answer your question; if you like the priesthood because it offers a secure job with a steady paycheck and good health benefits/retirement options then chances are you’re heading in the wrong direction. Likewise, if the appeal is based on being “in charge” or the centre of attention, then again something’s probably awry.
These probably don’t apply to you but it is worthwhile asking exactly what it is about priesthood that appeals to you on both spiritually and personally - this will help guide your discernment. As others have said, a call is a two way street - no one determines it by themselves, instead it requires confirmation from others and also testing. That’s what the seminary is for - to test your call and assist you in your ongoing discernment. So entering a seminary doesn’t mean you’re going to be a priest, nor does it commit you to anything significant and lasting (yes, it requires some initial commitments but nothing really binding - you can walk away at any time). Along the way, there are set milestones which require further reflection on your part and affirmation on the part of the seminary formation staff, all ultimately leading (God willing) to Holy Orders.
The main thing is simply to take it one step at a time - don’t try and get ahead of yourself. Of course you need to have a desire to follow where you believe God is leading you but you also need to remember that that might not be where you expect.