You do not have to start at Book #1. While purists will disagree, the series was designed with "cutting points" for new readers. Here are the best places to start reading Perry Rhodan books in order if you cannot begin in 1961.
For decades, the only way English readers accessed Perry Rhodan was through the iconic Ace Books paperbacks. These are numbered 1 through 37 (plus a few specials). If you are a vintage collector, this is you need.
(#1–49): Humanity's first contact with Arkonides and the unification of Earth. Atlan and Arkon