A Favor
Upon returning to your Digi-Farm, Azulongmon commends you and informs you that your Digimon must acknowledge you as a Noble Tamer to become a Bronze Tamer. Not knowing what to do next, Calumon tells you that a good way to do this is to complete Favors from your Digimon. While at it, Calumon also asks a favor of you to get a Digi-Cake in Training Peak.
Training Peak
You go to Training Peak using the green portal in Digi-Central. After reaching Training Peak(2), you obtain the Digi-Cake, but you meet two other Tamers, named Kain and Tomomi, who also want the Digi-Cake. Refusing to give it up, Kain challenges you with his Ultimate Digimon. It is at this time, a Tamer named Yuji shows up and saves you from Kain's Digimon.
Kain and Tomomi hastily retreated, and you thank Yuji for his help. You also ask him how to become a Noble Tamer, and he informs you that you need to train your Digimon in the Digi-Farm, and Digivolve them. Afterwards, Yuji bids farewell, and you return to the Digi-Farm to give the Digi-Cake to Calumon.
Extra Tip: As of now, you can only explore up to Training Peak(2). The other areas of Training Peak are not accessible yet.