It sounds like what you have is more of a portal than a wormhole, but that's just semantics really. You left the
science-based tag out so let's see where we can take this. Apart from the portal itself, I'm going to assume that physics is mostly the same.
The idea of dropping the other side into the corona of a star and letting the energy pour out of our side would be great if you wanted the energy for something, but you'd have to do something more to get thrust that way. You can't just point your portal aft of the ship and start thrusting since the energy passing through the portal isn't actually pushing on the portal or the ship itself. It's not like in a rocket where the exhaust gasses are pushing against the rocket motor to generate thrust, and conservation of momentum doesn't really apply since the other side of the thrust is in fact in a different universe.
So instead you'll need to interact with what's coming through in order to derive some thrust from it. Point the portal forward into a set of curved tubes (of some refractory material that can handle the temperatures) that redirect the transferred material backward. Turning the mass around will generate thrust, and you can probably steer a bit if the tubes can be moved or valved in some way.
Or you could use a variation on the solar sail concept where you have a lightweight sail that you direct the flow of matter/energy into. It would probably have to be a bit tougher than the average Mylar sheet though. Perhaps a rigid parabolic or conical structure with the point aimed directly into the mouth of the portal so that it scatters as much of the material to the sides of the ship so that you don't get fried.
Depending on the nature of what's coming through perhaps you could just direct it down a tube with permanent magnets and use magnetic drag to get some thrust. It'd look weird having your apparent thrust pointing forward... but weird isn't necessarily bad.
There might be a simpler way though.
If your portal essentially joins two regions of space in different universes then things like gravity may pass through as well. You could position the other side near a suitably massive object like a neutron star and have a gravity well form on this side. Your ship accelerates in the gravity well, pushing the near side of the portal ahead of it. You control the rate of acceleration by moving the other side relative to the mass you're using. And since your ship would be essentially in free fall relative to the gravity well you wouldn't have to worry about acceleration stress on your crew. Maybe some tidal effects though, so be careful getting too close to the portal.
On the other hand, if gravity doesn't transmit through the portals then you'll have to use the lessons we all learned in Portal 2...
Take two pairs of portals. Place the far ends of both in a gravity well so that an item exiting from one will accelerate towards the other. On the near side put the portal exits inside your ship's engine so that objects cycle through a short part of local space before going back through the loop. Drop something into the 'down' portal and bleed energy off with magnets or something.
You could also push a tube through the 'down' portal and grab the end as it comes back through the 'up' portal. Fill the tube with water or something, which will immediately start to flow through the tube due to the gravity on the other end. Attach both ends of the tube to a machine that will brake the flow, extracting kinetic energy from the loop. Maybe have a turbine in-line that you can use to generate electricity at the same time. Make sure you can stop the flow when you want, and that you can rotate the whole assembly to get directional control.
Now, as long as you let the water flow you'll have both thrust and limitless energy.
Which is why we know Portal is just a fun game. Physics doesn't like it when we break the rules like that.