Check my Grammar

I think your sentence is too long which is difficult to be understood. Also, there are some wrong use of words and I've revised your sentence as follows:

During the college period, i have gained a lot of concrete knowledge and practical skills in the area of company secreatary. All these have further equiped myself with a good attitude which is necessary for my future job.

I have gained a lot of useful knowledge and practical skills in the area of company secreatary during the college period. These knowledge and skills further developed myself with a good attitude for which is necessary for my future job.

I must be cap. letter