start with a program like couch to 5k, you should probably slow down aswell. going as fast as you can (aka sprinting) is quite an unsustainable starting out.
Tor Browser in normal mode is quite usable though, you just can't use extensions and you need to start a new session whenever you use other websites so they can't track you via cookies. Mullvad Browser is quite similar too.
c/BrandNewSentence