Information is the power. To know what your competitor doing creates for you informational power, which you can use in order to improve your current strategies or introduce some new strategies based on the information. The information can be taken from the internet. The resources you can access is libraries, universities and databases. Next source is the government. They usually sell information at low price. Even if it is public and even if it is free, local agencies still charge money for they work. The good source of the information is various associations, such as trade chambers, professional units for particular industry and other sales constitutions which represents usually indirectly government. Another source is magazines, journals, newspapers, radio, television. They usually have information about general trends in your niche. Next point to note, is universities. A lot of them perform research and sell it for the businesses. You can get this information directly from them or they representatives. Another point to note, if we look at your biggest competitor, we can get information in form of annual report. They usually reach of general information on various trends and future suggestions, about what future trends will be in similar to you industries. Before choosing what information is good for your business what is not, think if you can identify what is truth and what is not. My personal choice it is to use information from any source, as the data for the thinking, but not for strategy implementation. Every company have different requirements, so the data what you buy form other sources more likely will not fit you company. But...like I already say, businesses can use this data as the starter for the brain activities. In some cases if you know something you will repeat, if not then it will be feed for your brain.
https://www.bestnes.com/post/where-to-find-information-about-your-competitor