I keep my RH between 50-58 during veg and 40-50 during flowering first month or so then I drop low as I can, one way I control my RH is by trimming my plants, if the room is small and there's a lot of big plants RH becomes an issue to control, unless you buy a big commercial dehumidifier, the regular 70-90 pints Cant keep up without pruning the big fan leaves.
I use Inkbird Pre-wired Humidifier Dehumidifier, it's $35 an works better then the $200-400 hydroponic versions aimed towards marijuana growers, way over priced!! I also use Bayite BTC211 1650W Digital Temperature Controler for the temperature, you can hook up exhaust fan and heater to it, or Portable AC it works great, the calibrations on both devices are off, but you can calibrate and waaalaaaa under $100 u got a fully controlled room!!