The Elementary Principles of Nature below are as set forth by Epicurus and summarized in English by Norman Dewitt in his book “Epicurus And His Philosophy.” This list is provided for convenience. For discussion of each item, please see the forum devoted to each one.
PN 01 Matter is uncreatable.
PN 02 Matter is indestructible.
PN 03 The universe consists of solid bodies and void.
PN 04 Solid bodies are either compounds or simple.
PN 05 The multitude of atoms is infinite.
PN 06 The void is infinite in extent.
PN 07 The atoms are always in motion.
PN 08 The speed of atomic motion is uniform.
PN 09 Motion is linear in space, vibratory in compounds.
PN 10 Atoms are capable of swerving slightly at any point in space or time.
PN 11 Atoms are characterized by three qualities: weight, shape and size.
PN 12 The number of the different shapes is not infinite, merely innumerable.
Note the somewhat different reconstruction of this list by Diskin Clay: "Epicurus' Last Will and Testament" - by Diskin Clay
Discussion of this topic is here: The Twelve Fundamentals - Discussion on Lucretius Today Podcast