Each level will have its level ID next to it, so if you want to play it in isolation or practice it you can.
World 1
1-1: Let's-a Go! (LH3-9L2-VMG)
1-2: Into the Underground (SBF-GYT-MKF)
1-3: Pipe Hills (NX7-8NG-KSG)
1-4: Into the... Water? (D8T-7W5-C3G)
1-5: Lemmy's Bumper Bouncehouse (LR1-B29-VJF)
World 2
2-1: Buzzy Beetle Cavern (JBY-PTC-HKG)
2-2: Water Balloon Lagoon (61P-J23-9VF)
2-3: Parabeetle Dome (JXN-JW7-XHG)
2-4: Secret of the Boomerang Flower (4XT-CXM-MNG)
2-5: Larry's Lava Bubble Lair (GRJ-Y4K-KFG)
World 3
3-1: Ant Trooper Woods (NXM-X30-SDG)
3-2: Foreign Fungi (NBS-R5B-X4G)
3-3: Fortress in the Forest (GC0-4GT-4RF)
3-4: Midnight Poison Ivy (0J4-T33-VMG)
3-5: Iggy's Switch Palace (29D-WC5-V8G)
World 4
4-1: Spike Snowball Fight (SXB-NK4-SNF)
4-2: Swimming Through the Glacier (SLH-742-CTG)
4-3: Freezy Flake Cave (8JD-8BG-H6G)
4-4: Flying over Freezing Skies (46L-3HR-44G)
4-5: Wendy's Freezeflame Villa (LF0-8JZ-VWF)
World 5
5-1: Spiky Spiny Desert (06F-DCX-RRG)
5-2: Sun-Bleached Sands (X8T-5MX-60G)
5-3: Fort Bob-omb (DJ3-0SL-HGF)
5-4: Evening Desert Winds (SX8-PJT-PJG)
5-5: Morton's Squish Kebab Castle (QPK-CL5-V8G)
World 6
6-1: Enter the Propeller Box (B9G-1PF-0DG)
6-2: Sky High Koopas (B1V-9T7-VWF)
6-3: Fight the Koopa Prince! (DV0-S26-9HF)
6-4: Small Platforms, Big Mushrooms (D6S-KNT-PJG)
6-5: Roy's Bill Blastin' Bunker (4J7-71R-2JF)
World 7
7-1: Fish Bone Belt (6YR-6QJ-2MG)
7-2: Abandoned Boo Nebula (S85-G61-7MF)
7-3: Galactic Magic Trick (J6W-9RC-0RG)
7-4: Shimmering Starship (867-VWL-28G)
7-5: Ludwig's Snake Block Outpost (VRY-543-S1G)
World 8
8-1: Storming the Castle Walls (2YX-S6Q-KPF)
8-2: Red-Hot Haunt (NSP-VWR-PWG)
8-3: Approach the Final Castle (QCD-Y5B-FBG)
8-4: Bowser Jr.'s Airship Ambush (6MJ-FG6-9HF)
8-5: Bowser's Grueling Gauntlet (29V-LH9-CQF)