Hi @MichelaRiba,
Re-analyzing the old data with QIIME 2 might be the easier feat to accomplish... qiime1 is no longer supported or maintained, and some of the dependencies are no longer available, so installing qiime1 in 2021 is a challenge. You could check the forum for similar issues:
And if there are any virtualbox images on the qiime1 website that might be the most reliable way to install...
Anecdotally, I know a few labs who keep a dusty old computer around because it has a working qiime1 installation, just in case they need it 