Recreational/Hobbyist pilot was flying UAS in an area restricted by state law.

On Date at approximately XA:00 Hrs, I was in Olympia, WA for an unrelated event and decided to see if I could fly my drone on the Capitol complex to take videos or photos of the legislative building for recreational purposes. I checked the airspace using the ALOFT B4UFLY app, and could see that the airspace near the Capitol was Class G, but very close to Class E airspace for OLM to the south. I saw no signs or warnings of NO DRONE flying Zones. The areas for which I would take off and land were either flat, mowed grass, or empty concrete sidewalks. The temperature was in the high XA's, low XB's, and the skies were clear with a light breeze out of the south. There were very few vehicles or people in the area because the State Legislature is not in session currently. I parked on N Diagonal road and took off from the sidewalk area there. I completed 4 flights. I maintained VLOS for all my flights. The first I took off from the sidewalk near where I parked, and I elevated to 200 feet AGL, and then flew a path to the Winged Victory Monument and circled it before I returned to the area I took off from. I also walked down to the area in between the Legislative Building and the Temple of Justice and took off from the flag pole area directly in between. I elevated to approximately 330 feet AGL and completed about a 100 degree panning video to the north side around the dome of the Legislative building and then centered the drone and landed in the same spot I took off from. I did this twice for video purposes. Again, I landed safely back where I started. I then took off from mostly the same spot in between the buildings facing towards the Temple of Justice. My focus was on taking a video of the Temple of Justice from the south side of the building while I placed the drone at the same height as the tallest flag pole on the building, then scanning down the front. My last flight I walked back to where I originally parked my vehicle on N Diagonal, then I took off again from the sidewalk area and flew around the Tivoli fountain over the grassy areas, never going higher than approximately 150 feet AGL. I had no problems or concerns at the time during these flights. Now, 5 days later, I am speaking to a friend who is also a drone operator, but also a commercial pilot about my recent drone flights. After discussing these flights, he stated that it was not authorized to fly a drone on the Capitol complex. I said I checked the B4UFLY app, and did not see any signs or postings while on the grounds of the campus. Following our conversation, I then went and did more research now looking at non-aviation sites, as well as searching Sectional Aeronautical Charts on a commercial website and found that it is indeed not authorized to fly on the Capitol grounds and apparently numerous areas around there. I also then went an checked an aeronautical section chart (learning to read them) and do now see that there is airspace restrictions over the Capitol complex. My friend advised me I should report this incident to help ensure others like me potentially won’t make this same mistake. As a recreational pilot, who is working on getting my Part 107 certification, I have been attending training using the FAASafetey.gov site, and am operating under the understanding that any airspace restrictions, would be listed on the B4UFLY app. This is obviously NOT accurate. Following my friends notification that I may have violated airspace, I checked again on the B4UFLY app and again found no Special Use Restrictions, no TFR's, or any indication of not being able to fly on the Capitol grounds in the areas I flew. It was an open area and clear weather. The Class E restrictions appear to start to the south of the building. I would have never even considered flying if the Legislature was in session due to the amount of people on the ground and in the area. I will continue learning where to best get information about the areas for which I am permitted to fly and abide by the restrictions I am aware of, or should be aware of. I think this can be avoided for others in the future if the training for recreational or Part 107 pilots via the FAA, included ALL the locations to gather flight data prior to flight. Additionally training on the clear expectation that flying a drone requires you to know, use and understand Sectional Aeronautical Charts, as well as placing that information in the most accessible place to Recreational pilots. I have downloaded and used all the apps for flying a drone that have been pushed to use by the FAA on their websites. In my course of attempting to earn my Part 107 certification, I have taken the classes through the FAA websites to prepare me, and I feel very unprepared given this mistake I apparently made. I of course want to do the right thing, fly safely, and abide by the rules. I will continue to make efforts to learn and improve.