Hola Camila, I think I found a way to remove these tags from the Twitter before you process the data. I called the Twitter string t. Then this seemed to work; however, I only tried this on a short segment of your Twitter string so it is possible there are other patterns that may also need to be excluded. Good luck.

StringDelete[t, Shortest["RT@" ~~ __ ~~ ":"]]

I think this might work for you - I do not have a Twitter account and I am hoping to see what you come up with.

First, I copied your stepwords list, and converted it into a string and then into an association:

To get it into String format:

stepspStep1 = ToString /@ stepsp;
stepspAsString = StringJoin[Riffle[stepspStep1, " "]]

Then create an association as a WordCount:

stepsspAsWordcount = WordCounts[stepspAsString]

Then I took a piece or your Twitter data and created a WordCount association as well:

shortTwitter = WordCounts[t]

And then just took the complement of the keys from the Twitter with the stop words:

shortList = KeyComplement[{shortTwitter, stepsspAsWordcount}]

You can create a WordCloud directly from the shortList:

WordCloud[shortList]

I did notice that one should probably move all letters to lowercase because "Todo" slipped into the WordCloud.

Good luck.