You can download the Twitter Samples from https://www.nltk.org/nltk_data/.
Or by running the following code in python:
import nltk
nltk.download('twitter_samples', download_dir='.')
This results in the following structure:
.
├── README.md
└── corpora
├── twitter_samples
│ ├── README.md
│ ├── README.txt
│ ├── negative_tweets.json
│ ├── positive_tweets.json
│ └── tweets.20150430-223406.json
└── twitter_samples.zip