In these Vedas, you will find karma and certain kinds of visualization practices. These are not quite like the meditations that we do today. They're called Vidya, Karma, Vidya or Upasana. There are other associated sciences which helped the Vedic people to understand and use the Vedas. For modern Indians, shiksha would mean education, but in the Vedic context, it meant chanting the Vedas properly with correct pronunciation.
Swami Sarvapriyananda teaches the Mundaka Upanishad which one of the major Upanishads belonging to the Atharva Veda. Mundaka means ''shaved'' like a shaved head. The teachings revealed in this Upanishad are meant to leave the student clean, or shaved of the veil of ignorance. Indeed, the study of this Upanishad has been traditionally confined to the shaven-heads, or the sannyasins, who have renounced everything and devoted themselves exclusively to contemplation. The book consists of 64 Mantras (verses) split across Mundakas (parts) and Khandas (sections) as follows:
Mundaka 1 - Khanda 1 - 9 mantras (1.1.1 - 1.1.9)
Mundaka 1 - Khanda 2 - 13 mantras (1.2.1 - 1.2.13)
Mundaka 2 - Khanda 1 - 10 mantras (2.1.1 - 2.1.10)
Mundaka 2 - Khanda 2 - 11 mantras (2.2.1 - 2.2.11)
Mundaka 3 - Khanda 1 - 10 mantras (3.1.1 - 3.1.10)
Mundaka 3 - Khanda 2 - 11 mantras (3.2.1 - 3.2.11)
Reference books:
1. Mundaka Upanisad translated by Swami Gambhirananda - https://www.vedanta.com/store/mundaka-upanisad-with-the-commentary-of-sankaracarya_moreinfo.html (or)
2. Eight Upanisads Vol. 2 translated by Swami Gambhirananda - https://www.vedanta.com/store/Eight-Upanishads-Commentary-by-Shankara_moreinfo.html