What chapter should I start reading Blue Lock from after the anime?
Start at chapter 150. The anime adapts up to chapter 149, so chapter 150 is the first page of story the anime has not shown.
How many chapters is the Blue Lock manga ahead of the anime?
207 chapters. The anime covers through chapter 149; the manga is at chapter 356.
Does the Blue Lock anime have filler?
Every aired episode on record maps to specific manga chapters, so there is no filler arc to skip. The episode-to-chapter map on this page lists exactly which chapters each episode adapts.
Is there a Blue Lock season 3?
Yes. BLUE LOCK NEO EGOIST LEAGUE is in production and has not aired yet.