Moving a camera with follow path constraint


I’m trying to make a camera move along the path, and I’m having a hard time using follow path constraint.

Whenever I tried to make an object follow along the path, they move to somewhere far away, attached to the original path in a weird way with a blue line. So I’ve been using Parent->follow path since then.

But now, I really got to use follow path constraint because I’d like to move a camera, with their lens tilting along the path. This should be easy, right?

I searched about this problem why follow path constraint does not work properly, and found out many people suggest to apply a new location&rotation or do something with the origins of the path. There is something I don’t understand about this.

I understand that parent->follow path will need to make a path’s origin and the object origin to be in the same location. So I’d set the path origin to usually the start of the path by shift+S and select the verticle to the 3D cursor and then moving the object to it, and etc…

But I have no idea how this follow path constraint works. Should I edit the path origin as I did with parent->follow path?

I’ve seen much advice to re-apply the locations and scales of the path and object… re-applying these stuff will ruin edited origins from selecting verticles. For example, if I re-apply location to the path I’ve already edited its origin, the origin will automatically change, like ‘origin to geometry’. So, in this case, the origin will be placed in the middle of nowhere, since my path is very curved.

What’s even more, the object I’m trying to move is a camera. Which means I’ll have to think about how the lens will tilt naturally by the path. Re-applying locations and rotations to a camera does not work like objects too.

I’m very frustrated because this seems to be easy, yet I can never understand how. Could anybody let me know how this ‘follow path constraint’ actually works? If I can make it work, I’ll be thrilled.

I’ll post the blend file through Google drive. you can ignore many axes.

L3DtrackerCameCC1.001: the camera I’d like to move
BezierCurve.001: the path I’d like to make the camera move along

If anyone has advice or suggestions, I’ll try everything.
Sorry for my grammar. I haven’t slept very well recently and my writing can be a bit weird.
Thank you!