Will RF cause any health problem?
There are two actions through which electromagnetic radiation can cause health problems.

If the radiation is ionising (ie has a high enough energy to liberate electrons from their atoms) then it has the potential to cause wide ranging unpleasant effects. Fortunately EM radiation is only ionising at frequencies somewhere in the far ultraviolet region - not an issue for RF applications.

The other way that EM radiation can cause damage is through dielectric heating. This happens over a range of frequencies, and is the method that a home microwave uses to heat food. At the frequencies that you're dealing with, this is the only potential vector for health issues.

Whether the RF radiation you're dealing with can cause health issues is completely down to the power levels that you're using. Most RF emitting devices you use in your home (WiFi router, garage door opener, hobbyist RF transceivers etc) only transmit a maximum of a few hundred milliwatts of power. A cell phone might transmit at 2W. Thanks to the inverse square law, the actual power of the transmission that can possibly interact with your body drops off with a square of the distance (and so very quickly). The efficiency of that RF in heating your body will also be considerably less than 100% (you could probably work this out using the heating equation given in 1). This all adds up to a very small amount of the transmission power actually being absorbed by your body. For reference, the body apparently generates about 1W/kg of heat while at rest, rising to 2-3W/kg while active. The very small amount of heat generated by the RF will be easily dissapated by your body's existing cooling system (you are incredibly effective at maintaining a stable temperature), and is dwarfed by the heat generated by muscle movement.

So to summarise? If you're dealing with standard consumer RF transmitters, you're safe. If you've built an RF transmitter which could potentially broadcast at high power levels, then you could experience adverse effects.

It's always worth noting when discussing this topic: 1. Humans have only been routinely carrying RF transmitters close to our bodies for a couple of decades. It may be that time shows us that this isn't a great idea, and 2. There's a lot of crazy people who will say a lot of stuff on this topic that is wrong. The kind of low power RF transmissions used for WiFi are exceedingly unlikely to have any effect at any distance. Every study I'm aware of has demonstrated in double blind tests that claimed "electromagnetic sensitivity" is entirely psychological.