Paleogenetics looks for commonalities across the branches of life. Some of the most ancient molecules, which occur across all forms of life, have vestigal peices of RNA attatched. These molecules are even important to human nutrition - some of them are in the multivitamin pill you take every day. In each case, the RNA part that's attached doesn't participate in its chemistry, but the fact that RNA parts are conserved throughout species tells us that they were probably around at the time of the Last Universal Common Ancestor (LUCA). This is where the record stops, where paleogenetics hits a dead end. All of the evidence that we have points to a form of life with RNA but no proteins.
Prebiotic Chemistry starts from the other direction. An experiment starts with the chemicals and conditions present on the early Earth before life emerged (hence, Prebiotic). The most famous prebiotic Chemistry experiment was caried out by Miller and Urey at the University of Chicago and published in 1953. They mixed only simple molecules, and added heat and electrical sparks to simulate lightning. What came out were amino acids (which, as discussed before, are the building blocks of proteins). At the time, this experiment was very influential, convincing many that the molecules of life are an inevitable result of planetary formation.
However, the Miller-Urey experiment generated its amino acids in extremely low yield. Mostly it generated quite a bit of tar, a substance that is fine for paving roads but cannot form life. When the Miller-Urey experiment generated amino acids, it was before the discovery of catalytic RNA and the postulation of the RNA world. It is also worth noting that the Miller-Urey experiment generated no RNA-containing components.