I can't recommend a 4/32 device to a new OpenWRT user for much of anything, not to mention anything in the future. They're too small and too underpowered for general use. You can't run much more than wireless, basic routing and DHCP/DNS from dnsmasq on them. See https://openwrt.org/supported_devices/432_warning
While I don't have experience with the units, the WR940N is not one that I'd recommend.
See also, for further ideas and opinions, the (long) thread