Hi Welcome.
Travel - For most, one lens like 18-200 f3.5-5.6 that do it all is preferred for travel phoography, saved u the hassle of lens changing with the drawback of variable aperture (tat doesnt allow u to optimize ur shots in low or trickly lighting conditions.)
Macro - get an dedicated macro lens , u need to be precise though, wad kind exactly?Flora or Bugs? As diff focal length serve diff purpose. We have 602.8, 100 f2.8, 105 f2.8, 150 f2.8 ,180 f2.8 (both canon and 3rd party's to name a few) Hope to achieve higher magnification? MPE65 is ur answer..
Nature - like above, too brief. Want to shoot wildlife?Bird photography? U need at least a 70-200 with TC for that extra reach, else u have to look at telephoto primes if you have the dough. (we have 300,400,500,600mm) if not u shd take 3rd party's options into considerations.
HTH