Starting an advertising business as a startup is simple. You must identify your niche. You should research your target audience. You need to create a business plan. You must set a budget for your expenses. You should register your business legally. You need to build an online presence. You must create a portfolio to showcase your skills. You should network with potential clients and partners. You need to focus on delivering quality services. You must track your progress and improve constantly. You should stay updated with trends in advertising. You need to remain consistent in your efforts to grow.