You can test many different setups, different number of ads groups or ad sets but the most important thing is your product, offer, landing page and creatives and to understand your metrics which is an inductor of how your ads are performing. For example;  CPM means cost per thousand views. That's how much Tik Tok charges you every 1000 views your ads get. CPC means Cost per Click. That is how much Tiktok charges you every time someone clicks on your ads. CTR means Click Through Rate. That is the percentage of clicks you get to your site compared to the number of views. It's usually a good indicator if Tiktok is charging you a  low CPM and your CTR is good. However it's very important that your landing page, product and offer is great. If you have a marketable product, a convincing landing page and a good offer, people will be more likely to purchase from you!