INTERNET
Today, computers and the Internet have become key elements in the lives of most people. For many, it's hard to imagine a world without his smartphone, without WhatsApp or without email.
In my life, computers play a fundamental role. With the PC as my working tool, thanks to the Internet I can do many things easier than before. For example, I can look up a job, update my design portfolio on specialized websites, communicate with friends and colleagues, keep up to date with news about design and architecture, etc. And, of course, I can also listen music via streaming and watch online series. Now, I rarely watch TV.
And, why not say, I love social networks. I think they offer a great way to keep in touch with both friends and unknown people with common interests or hobbies. They allow infinite knowledge sharing. With Twitter, for example, you can know the news almost the minute they happen, long before they appear in any newspaper. That's fantastic! But my favorite is, undoubtedly, Pinterest. In this social network, art and design professionals can find a great source of inspiration.
However, social networks also have important disadvantages. On the one hand, our privacy is more and more compromised. On the other hand, we have less personal contact with our loved ones. We hardly talk on the phone. When we meet with our friends for coffee, the mobile phones and WhatsApp are as much protagonists as the conversation. That is really sad!

INTERNET

Today, computers and the internet have become key elements in the lives of most people. For many, it's hard to imagine a world without his a smartphone, without WhatsApp or without email.
In my life, computers play a fundamental role. Besides the PC is being my working tool, thanks to the internet I can do many things easier than before. For example, I can look up a job, update my design portfolio on specialized websites, communicate with friends and colleagues, keep up to date with news about design and architecture, etc. And, of course, I can also listen to music via streaming and watch online series. Now, I rarely watch the TV.
And, why not say, I love social networks. I think they offer a great way to keep in touch both with friends and unknown people (or strangers) who have interests or hobbies in common. They allow sharing knowledge in an almost infinitely infinite way. With Twitter, for example, you can know the news almost the minute they happen it happens, long before they the stories appear in any newspaper. That's fantastic! But my favorite is undoubtedly, Pinterest. In this social network all art and design professionals can find a great source of inspiration.
However, social networks also have important disadvantages. On the one hand, our privacy is more and more compromised and, on the other hand, every over time we have less personal contact with our loved ones. We hardly talk on the phone and when we meet up with our friends for coffee, the mobile phones and WhatsApp are as protagonists prominent as the conversation, that is something really sad!

Excellent work Inma! My corrections are in red and my suggestions to sound more natural are in blue/grey.

The rules for "besides" are a little bit strange. You could say either:

"Besides the fact that the PC is my working tool" or

"Besides the PC being my working tool".

You can say "both with friends and unknown people" or "with both friends and unknown people" (as Kristine suggested).

"News" is plural, but is used as if it was singular. So you would say "news happens".