OP, just go to the "bin" folder, open a terminal, and type "./bitcoin-qt" to run the client. Then control+C to stop it, then go to /home/"your name"/.bitcoin. Create a bitcoin.conf file, and start with, "debug=net", and "maxmempool=100" without quotes. Configure as your bandwidth allows.

Plus do you have limited disk space? Add "prune=10000".