It is better fo get your bachelor's degree first and then go for a masters after getting some experience.
There are several reasons for doing this:
- after some experience, you may have a clearer idea of which area in which you would like to concentrate in you masters, if you determine it is necessary ( it may not be, based upon your career view)
- your employer may assist with the payment of advanced training if it is beneficial to the employer, you, and your future goals (within or independent of your employment). It may not be a masters, but it could be something that is even more helpful for your career journey.
- employers generally do not look favorably on a candidate who has attained a masters without relevant work experience as they do not have real world experience on which to base their education.
You will get a clearer view after reading and following through on my answer to your other question.