Of course, we are assuming accuracy in testing. Your pH is high because your carbonates (as indicated by KH) are so high. This has nothing to do with GH, which is based upon calcium and magnesium. I would tend to want to bring the KH down by, at least, half. Many of us, including me, run at about 20 ppm, but we also use RO/DI water. Plants also tend to absorb nutrients best when the pH is in the 6-7 area. To do this, without CO2 injection, you will need to get the KH down into the 30 ppm region. Distilled/RO water is the way to do it. Having said this, however, you should still be able to grow plants,where you are, just not as robustly. Fish may be a different issue.
Regarding GH: yes, you will need to bring it up (which is also good for the fish). You can target anywhere from 30-150 ppm as a decent range. I'd suggest using a GH booster such as NilocG's or Seachem's products. These will also give you potassium, which is needed by plants.
Depending upon your fish load, you may also need to add nitrates and phosphate. You will certainly need to add traces, which are also available from these companies. There is much more to learn, but this answers your question and then some. You might want to consider getting the guide here on this forum.