In U.S., we can NOT go fishing suddely. Basically we need a license for fishing even for leisure purpose. Moreover rules on fishing are different depending on states, places, and kinds of fishes. So anglers need to check these regulations beforehand.
In my case, I live in California so I need to get a California fishing license. But don’t worry, it is not difficult to get it. You can purchase it from the website of California Department of Fish and Wildlife (CDFW)(https://www.wildlife.ca.gov/Licensing/Fishing)
If you visit the website, not only the license, you can get most of the information you want for fishing such as other rules and banning period. Moreover, it shows a lot of explanation about fishes as following picture, you will be exsited by them.
Regarding the licensing fee, as of 2017, people living in the state can get an annual license for $47. If you do not go fishing so frequently, it may be better to buy one day license for $15.
Also in California, CDFW provides Fishing Guide on the Web. It is very helpful to check regional rules and regulations such as type, size, and number of fishes you can keep.
(CDFW Fishing Guide)
Let’s go fishing with the license!