Here is a list of content that will help you learn the script.
A strategy that seems to work is to pick a basic word in a siNtu language. Separate the word into syllables. How to do this ? Each syllable ends on a vowel, so after each vowel, draw a line. You now have identified your vowel for each syllable. Write your vowels (triangles or chevrons). Now, include you consonantal features.
Use the online keyboard : https://isibheqe.org.za/demo/
and check with this app if you were correct : https://riker.itch.io/isibheqe-translator (This app works well for isiZulu.)
IsiBheqe website for siNtu explanations : https://isibheqe.org.za/
The wikipedia article in English : https://en.wikipedia.org/wiki/Ditema_tsa_Dinoko
Omniglot page : https://www.omniglot.com/writing/ditema.htm
Endangered Alphabets : https://www.endangeredalphabets.net/alphabets/ditema-tsa-dinoko/
You can also join the whatsapp group / FB page. Search online for these links with #Ditema tsa Dinoko / #isiBheqe Sohlamvu.
Videos