There are many words and phrases that can be used as synonyms for the phrase "just begun". Some options include "in its infancy", "at the outset", "starting out", "inception", "commencement", "nascent", "incipient", "embryonic", "preliminary", and "genesis". Using different words to express the same idea can add variety and nuance to your writing. It is important to choose the synonym that best fits the context and tone of your writing, and to avoid overusing any one option. By using a variety of synonyms for "just begun", you can keep your writing interesting and engaging.