Good hotels in San Francisco if you plan to do an independent walking tour.

I’m looking for an affordable hotel in San Francisco for an upcoming weekend. I’ve been to SF before, but only long enough to bike the golden gate bridge and call it a day. I’m looking to chill solo and walk around to explore the city a little more in depth. I’d like to book a hotel that is located close to some awesome area attractions that are easily accessed on foot/public transit, but I don’t know what areas in the city to shoot for. Any suggestions on hotels, points of interest in the city, or general areas great for foot traffic?