There’s a 1-Up in the Block at Point 2. It can be a bit tricky to get it, since the ground underneath it is frozen. If you have the Penguin Suit power-up you can jump over to it without any trouble. If not, get a slow running start, then execute a quick Spin Jump over the gap before putting on the breaks and steadying yourself underneath the Block. Jump up to pop the 1-Up Mushroom out, then leap through the platform to the right to grab it.
If you can’t reach the Bowser flag from the left, hop down to the area below it, then jump onto the ledge on the right. Bounce off the ledge to the flag on the left and pass through the flag.
Do not try to Gap-Dash across the gaps in Point 7; they’re too wide. Instead, carefully jump from pillar to pillar until you’re all the way across.