Comments on your original sentence: You don't normally carry out training 'with' staff. They are the recipients of the training. "...theoretical and practical skills" - this sounds odd. A skill is a demonstrated facility at doing something - not sure you can actually have 'theoretical skills". Given the last part - that the training is about company policy and procedures, it sounds more like the training is going to be about improving staff's knowledge and understanding rather than any practical skills. Therefore, I suggest the following revision: Conduct staff training to improve knowledge of company policies and procedures.

It would be useful to discuss what you want to say. If I had to guess, it would be this: "We plan to carry out staff training to achieve an improvement in their theoretical understanding and practical skills with respect to company policies and procedures."