I need help with my privacy

Hello,
i live with people who are not my family so i want my history and mac to be private and i use their router which is NETGEAR Rangemax WNDR3700 Dual Band Wireless Router and opera browser i use private tab for my private stuff and have firewall high mode on, so is there any possible way they can look into my history and stuff from the router or any where?
and they also have another one which d-link, i also use CCleaner once in a while and if there is any thing that can help me with my privacy please tell me.

Thank you

G'day and welcome to the forums.

First up trash CCleaner. Works well on Windows burr not on OS X. Download Onyx for whatever operating system you are using. You are pretty safe but if this worries you too much just get your own modem if you have your own connection.