Hi, @cristianomariacumer, and welcome to the forum! 
It looks like you may not be using the correct version of node. I would suggest reviewing the post here and following its advice first: Q2studio npm start error - #2 by andrewsanchez
Additionally, you should make sure that you are not overriding the node version that you should have installed with conda into your qiime 2 environment by looking at your PATH variable. You can check how your PATH variable is configured by sharing the output of this command (make sure your qiime 2 environment is activated before running these):
env
The output of this command would also be helpful:
conda list