Are there other way to know if your force sensitive without jedi?
And how does training worl?

To the best of my knowledge, there are two ways to determine force sensitivity.
1) A force user tests your connection to the force
2) Use a Force Detector item on yourself. Bear in mind these are only obtainable from bandit (NPC drops) or purchasing them from the market.

Force Training Rules Page

As for training, there are three ways to train in the force:

Training with a Master
Training without a Master
Training using a Holocron Edit: Not implemented, thanks Jay.

Scratch number 3 from that training list til it's implemented.

I can accurately describe force training client-wise in a few simple words.

Sit still, push button, wait for an hour. Success can be anywhere from 20%-90% if you have a master.

“2) Use a Force Detector item on yourself.

- Eli
 ”

Does it still work if you do not own the Force Detector?

It should work regardless of ownership, particularly as you can use it on others and not only on yourself. But given that things don't necessarily work as they should here, please let us know if you observe different behaviour.

It needs to be equipped to a utility slot in order for you to see the Use Item option on your equipment page.