Early Buddhism focuses mainly on the suttas. There’s rather a lot of them 
, so a good sutta anthology might give a good feel for these without having to do an enormous amount of reading. Bhikkhu Bodhi’s In the Buddha’s Words would be a nice example and a good start point, but there are some other options (some online and downloadable - I list a few in an old post here).
Bhante Sujato has some very nice books (free and online) on Early Buddhism, e.g., A History of Mindfulness, giving an idea of the whole area (with some books more focused on the theme of meditation like A Swift Pair of Messengers). Early Buddhism is usually concerned with trying to figure out what the pre-sectarian Buddhist teachings were (before Buddhism split into different schools and things diverged a bit). We have versions of most suttas from more than one early schools (often in Chinese and sometimes Tibetan and other languages, not just in Pali). There’s a lot of similarity between the different versions but differences too. Things that are common to all versions are more likely to be earlier.
For meditation approaches influenced/inspired by Early Buddhism, I find personally writings by Bhikkhu Analayo helpful. He’s a scholar monk who spends a portion of each week just meditating and another portion writing books and academic articles (an interesting blend of theory and practice). He has several books on various types of meditation: anapanasati (breath meditation), metta (loving kindness meditation) and satipatthana (mindfulness meditation). In many of these books, there is often a section in the later half where a selection of passages from the suttas on the topic is explored (usually with his own translations from Chinese or other versions of the relevant suttas as well as the Pali versions, often looking for common elements) with a large part of the book then describing a meditation approach he has developed for himself inspired by this learning (turning some of these ideas on early Buddhism into a practical and usable meditation practice). Analayo is a big one for guided meditation audios for these techniques (he usually releases free guided meditation audios online for such books).
On other practices like chanting, Theravada (the type of Buddhism practised in countries like Thailand) might be a place to look (it’s the closest existing school to Early Buddhism, though they are not the same – see an interesting list of the differences by Bhante Sujato here). For example, a nice source of chanting can be found on the Amaravati website (a UK Theravada monastery in the lineage of Ajahn Chah). There’s a chanting book and corresponding audios (many in English, as well as in Pali too):