Space-tourism website using reactjs

I didn't do this in much detail, but nonetheless have finally finished making this project after a long time of procrastinating, I also learnt reactjs in the mean time, so I used this project to put my skills into practice. I seem to have a few problems with my code and website, one being the issues with the buttons on the last page, it raises an issue when i first click a button saying cant read the classlist of null, however after i click off the error everything seems fine and everything starts to work, also I didn't keep the heights of each page consistent so that I would say is another minor issue in its self, I also didnt make this responsive (i didnt make a mobile version) as I really want to make another project so i just left it as the desktop version. Anyway please give feedback and now ill be starting on the to-do list project :)