I think you're off to a ok start. Don't take it the wrong way, Rome wasn't built in a day.
From your port, I feel like your strongest stuff is when you're not actively trying to present people in a certain. Like this one:
<-- its a beautifully, honest captured moment
I also like this one...
...for different reasons. You had an idea & went w/ it full-throttle (or at least it LOOKS like you had an idea).
When you try & half-ass something either not quite going after a specific idea or not quite letting the moment happen, it glaringly shows.
1. Keep at it. Practice makes perfect. & practice A LOT, so much so that at some point you could do portrait work in your sleep.
2. Do some homework. Spend some time looking at people who do actor headshots & how (if they're good), they're able to get the actors to connect w/ nothing but the X-factor in their eyes.
3. Do more homework. I highly encourage you to look at the past photographic masters like Arbus Bourke-White, Weston, Steigleitz, Avedon, & Eisenstaedt (to name a few) & see how each of them connected w/ their subjects & how they differed.
I'd also encourage you to look at classical painters like Da Vinci, Rembrandt, Vermeer, Raphael, Jacque-Louis David to name a few. Pay particular attention to how they composed their works as well as observing their sense of light.