After you get the Icicle Badge at Snowpoint Gym, you can check on your friend at Lake Acuity.

Explore the Lake

When you arrive at Lake Acuity, there will be a cutscene. Afterward, you can Surf in the lake. While Surfing, you can encounter Psyduck and Golduck. If you use the Old Rod in the water, you can catch Magikarp. If you use the Good Rod in the water, you can catch Goldeen and Magikarp.

Surf northeast to find some grass. While walking in the grass, you can encounter Bibarel, Chingling, Noctowl (night only), Psyduck, and Sneasel.

Go north through the grass and then northwest to find a TM14 Blizzard.

The cave in the middle is empty now, so you can use the Town Map to fly to Veilstone City. Go northeast to find Team Galactic HQ.