Hi @Mariana =)
What kind of skills exactly would you like to learn?
I'll give you a couple of general links while I wait for more information. =)
This is a good website to learn coding for web programming. I used it during my studies and they produce really good quality material
Here's a nice link with really good tips when start to take into account when starting blogging howbloggingworks.com . To blog you will also need to learn the basis of a blogging platform, for example wordpress.com/com-vs-org/ which is widely spread and used.
For what concerns Office skills, check out this link http://www.gcflearnfree.org/topics/office2016/
where you can choose about which programm you would like to learn more and get tons of gooooood quality video tutorial with also written explanation.
Are you trying to do it in your Free time or as a primary occupation? Tell me more about your goals and I'll try to find something that actually suits your needs =)