Using Google Translate API to create a Translation Dataset
It depends. Google Translate works very good with some pairs of languages, and not good on others. Based on my personal experience, translating from North-European languages (Dutch, Danish, Swedish) to English worked almost perfectly, while English-Italian translation lead to bad results.

You can find a Spanish-English dataset here, this is a very official source.

Additionally, it seems DeepL is a great German &lt;-> English online translator around.