Use the following instructions to start your wallet on Ubuntu Desktop 18.04.
Update your Ubuntu machine.
sudo apt-get update
sudo apt-get upgrade
Install the required dependencies.
sudo apt-get install build-essential libtool autotools-dev automake pkg-config libssl-dev libevent-dev bsdmainutils python3 libboost-system-dev libboost-filesystem-dev libboost-chrono-dev libboost-test-dev libboost-thread-dev libboost-all-dev libboost-program-options-dev
sudo apt-get install libminiupnpc-dev libzmq3-dev libprotobuf-dev protobuf-compiler unzip software-properties-common
Install Berkeley DB.
sudo add-apt-repository ppa:bitcoin/bitcoin
sudo apt-get update
sudo apt-get install libdb4.8-dev libdb4.8++-dev