Whenever I dive back into the old Archie 'Sonic the Hedgehog' comics, I like to treat them like a long, character-driven TV show rather than a pile of numbered issues. Start with the very beginning of the Archie run and read straight through the early volumes so you get the origin beats, who everyone is, and the tone that defines the rest of the run. That establishes Sonic, Tails, Dr. Robotnik/Eggman, and the early supporting cast, and makes later twists land much harder.
After you’ve got the foundations, I’d weave in the spin-off 'Sonic Universe' stories whenever a character gets their own arc. The spin-offs often deepen character moments that the main series sets up — so read the main series arc that introduces or focuses a character, then pick up their 'Sonic Universe' tie-in to see more of their development. Specials and one-shots work best after the related arc, since they often assume you already care about a character.
Finally, treat the big crossover and late-era material as a finale: read through the main series up to the major crossovers, then consume the crossover events and the final climactic arcs. If you’re collecting trades instead of single issues, follow the trade chronology of the publisher or a fan reading guide online so you don’t miss interleaved issues. All that said, the joy is in the characters, so if a side arc about Knuckles or Tails is calling you, jump in — the run is forgiving and full of fun moments. I always come away smiling.