Tokage (Hontou wa Shinryuu) wo Shoukan shita Seijuutsukai, Ryuu no Senaka de Kaitaku Life

Levin, a young man who was supposed to summon a sacred beast in a grand ritual, ended up calling forth a tiny lizard instead. Furious, the king exiled him from the kingdom. Guided by the lizard, Levin soon encounters a colossal dragon that carries an entire continent on its back!? As it turns out, this little lizard is actually a pure white Divine Dragon, and the vast continent on its back is her homeland. At the dragon's request, Levin takes on the task of developing the desolate Dragon Continent and restoring the lost capital of the Divine Dragon Clan. From building his dream home with mysterious magical tools to being healed by adorable sacred beasts, Levin embarks on a thrilling sky-high adventure, soaring freely between the heavens and the earth!

(Source: AlphaPolis, translated)