what It has to be done for training cap. what do I have to do. it' s just one day so I don't want more surprises because I did not know

The main things are:

* Make sure your coaching staff is in place
* Make sure you are not over the roster or cap limit, as this will be enforced
* Make sure any position re-assignments have been done, because this is the stage where the players get the most development at their position

Just put your guys on the depth chart and make sure they are in the positions that you want them to play. The sim takes care of the rest.

Actually the depth chart has no impact in TC, it is the assigned position (the position that shows at the top of the player's page) that matters.