Is your balance too low to spend?
All Bitcoin transactions include by default a network transaction fee which must be included to ensure a miner picks up your transaction and includes it in a block.
The amount of this fee depends on the size of the transaction as determined by a number of inputs and outputs, not the amount of money being sent. To send all the funds in your wallet, with the fee already calculated, just tap on "Send all".
If the amount stored in your wallet is lower than the transaction fee required to send it, you will not be able to send the funds until your wallet has enough of a balance to pay the required fees. (Note that even in this case, it may cost more in fees to send a small amount of BTC than the value of the transaction itself.)
Transactions on the Bitcoin Cash (BCH) network are much cheaper than on the Bitcoin Core (BTC) network, but the two networks are distinct. Funds sent from the BTC network will remain on the BTC network, and vice-versa, with BCH.
You can use this tool to calculate the recommended BTC network transaction fee at any given time.
Bitcoin Cash (BCH) fees are set by default to calculate at the lowest rate to be confirmed on the network (Usually only 1sat/B) using the Bitcoin.com wallet.
You can change the Network Fee of your BTC transactions in the "Settings" menu:
To change this just tap on the "Settings" cog in the bottom right of your wallet "Home" screen -> press on "Bitcoin network fee" -> You can select between Priority/Normal/Economy network fee and see the average confirmation times for the network fee you have selected. (These times only relate to BTC transactions)
Please read our Getting Started section to learn more about Bitcoin, how it works and how to use it.
You should also find our Bitcoin FAQ and Wallet FAQ pages very useful.