Thought I’d also chime in here! Agree with Matt here on the importance of periodisation and rest between races, but have to admit as a multisport athlete I have done my fair share of races close together so understand your situation!
How I like to approach doing races close together is, put these races into blocks and then I focus on training for the first race, recover, and then take that fitness I built from the first race and maintain and refine it through to the next one. So unless you really didn’t get in consistent training for the first race your best approach after the first race is to have a week of recovery (week of slow) to absorb the fitness from the last race and training block, then back to some foundational training for about 2 weeks, then 4 weeks of some race specifics again, week of taper and time to race again!. An important note is that you do not want to do this too often in your training cycle, and after the second race a good recovery and full build for the next race is recommended for the best performance and overall health outcomes. Matt gave a great example of how to adapt a 80/20 15 week half marathon plan when you have a shorter prep window.