SWTOR: Order to play classes, and planets by level

Planets by Level
Ref: https://swtor-archive.fandom.com/wiki/Planets

The 8 classes:
Possible to play all main quests first, then area quests.
Republic: Jedi Knight -> Jedi Consular -> Smuggler -> Trooper
Empire: Sith Warrior -> Sith Inquisitor -> Hunter -> Agent

Starting planets:
1-10 Korriban Sith Empire, Seat of the Empire, Starting zone for Sith Warrior(1) and Sith Inquisitor(2)
1-10 Hutta Hutt Cartel, Hutt Space, Starting zone for Imperial Agent(4) and Bounty Hunter(3)
1-10 Ord Mantell Galactic Republic, Mid Rim, Starting zone for Smuggler(3) and Trooper(4)
1-10 Tython Galactic Republic, Deep Core, Starting zone for Jedi Knight(1) and Jedi Consular(2)

Faction capitals:
10-16 Coruscant Galactic Republic, Core Worlds Prologue world (Republic)
10-16 Dromund Kaas Sith Empire, Seat of the Empire Prologue world (Imperial)

Republic? Taris 🡒 NTA 🡒 Balmorra
Imperial? Balmorra 🡒 NTA 🡒 Taris

16-20 (Republic), 32-36 (Imperial):
Taris Independent (Republic Controlled), Seat of the Empire Chapter 1 world (Republic), Chapter 2 starting world (Imperial)
16-20 (Imperial), 32-36 (Republic):
Balmorra Contested (Imperial occupied), Coreward Worlds Chapter 1 planet (Imperial), Chapter 2 starting planet (Republic)

NTA:
20-24 Nar Shaddaa Hutt Cartel, Hutt Space Chapter 1 world (both factions)
24-28 Tatooine Separated, Distant Outer Rim Chapter 1 world (both factions)
28-32 Alderaan Contested, Coreward Worlds Chapter 1 planet (both factions)

36-37 Quesh Galactic Republic, Hutt Space Chapter 2 world (both factions)
37-41 Hoth None (contested), Distant Outer Rim Chapter 2 ending world (both factions)
41-44 Belsavis, Galactic Republic, Distant Outer Rim Chapter 3 starting planet (both factions)
44-47 Voss Independent, Outer Rim Chapter 3 world (both factions)
47-50 Corellia Galactic Republic, Coreward Worlds Chapter 3 ending planet (both factions)
50-50 Ilum (🚩Base endgame) None, Unknown Regions Level 50 endgame content (both factions)

Expansions:
50-55 Makeb Independent (Hutt Controlled), Hutt Space Chapter 4 starting world (Rise of the Hutt Cartel, requires expansion, both factions)
55-55 CZ-198 Czerka Corporation, Unknown Regions Level 55 Elder Game Flashpoint content (both factions)
55-55 Manaan Independent, Core Worlds Level 55 Elder Game Flashpoint content (both factions)
55-55 Oricon Dread Masters, Seat of the Empire Level 55 precursor to Dread Master Operations (both factions)
55-58 Rishi Independent, Outer Rim Chapter 5 world (both factions)
58-60 Yavin 4 Sith Empire, Seat of the Empire Chapter 5 world (both factions)
60-65 Zakuul Eternal Empire, Wild Space Star Wars: The Old Republic: Knights of the Fallen Empire world (both factions)
60-60 Ziost Sith Empire, Seat of the Empire Chapter 5 world (both factions)
65-65 Darvannis Hutt Cartel, Eternal Empire, Hutt Space Star Wars: The Old Republic: Knights of the Fallen Empire Chapter 14 world (both factions)
65-65 Odessen Player Alliance, Wild Space Star Wars: The Old Republic: Knights of the Fallen Empire hub (both factions)
70-70 Iokath, Wild Space Level 70 daily and operation area (both factions)

General

See guide description.