Seniors, please teach me!

If you tap your character, it should make a sound, and that should guide you on your path... I think. All the portals are connected, so try starting from the leftmost portal, called the 'lonely island'! (It's been a long time since I played, so I apologize if it's changed due to updates.)

I'm not sure where the portal is (maybe the home base in the Flower and Bird area…?), but try walking around and exploring different places! As the previous commenter said, if you tap the character, they'll make a sound and a mark should appear indicating you should go this way ✌️ The tutorial isn't very detailed, so if you have any more questions, it might be a good idea to ask here with a screenshot or something 🤔

Since it's the Van Gogh collab this time, I think it'll probably spawn in the collab area. So, if you go through the sunflower portal in front of you, you can do the "Season of Van Gogh," and from where you spawned, there's a gray portal to the right? or left? If you go through that, you'll likely end up in the place with the six gates lined up, like others have mentioned 😊 Sorry if you've already cleared this area though (´-﹏-`；)

If this is your first time logging in, you're probably in the 'Story Room'. If you jump into the sunflowers, you can immediately experience the story of 'Van Gogh's Letter'. If you want to do other things, first go towards the back, and you'll enter a place called 'Kachoukyou' (Flower-Bird Village). From there, proceed through the stone gates in order from the left to the temple. You can move directly to the next area from the temple, so just keep moving forward. This game has autosave, so it's good to progress steadily. Feel free to ask if you have any more questions.

If you get stuck later, there's also a Sky walkthrough site on a wiki called '9Bit', so it's good to check it out. Some Sky players even call it 'Teacher Cubit'. You'll probably rely on it so much you won't be able to sleep facing that direction ( *´艸｀)