This TV is set up to connect to an external amplifier which that controls the speakers. It has an analog audio output which means you need an RCA audio cable (2 RCA plugs (red and white) on each end. You can't directly connect a set of speakers. The audio output jacks at between the antenna in and the video inputs. Then you need to enter the menu and enter the Audio submenu. Go to the Speakers item. Turn the TV speakers to off and fixed audio out.(The amplifier will adjust the volume.) Use the Up/Down arrows to navigate through the menu options, press enter to enter a sub-menu and the volume up button to change a setting.
There is also a headphone jack which may be compatible with computer speakers. That has a 3.5 mm jack. To use headphones, set the Speakers Audio item to TV speakers Off and variable audio out. (The TV controls will adjust the volume.)
To use a Universal remote to set the audio or modify the channel list, you need one that matches the Menu function of the original remote. You may need to try multiple codes for Panasonic TVs to get the button to work. Some low-end universal remotes may not have the menu button; get a different remote or use the menu button on the front panel of the TV.
To set the channel list, press Menu and select Setup. Go to the Prog Chan option. Then set your Mode in the first option (Cable or Air). Then choose Auto Program to scan all channels or Manual Program to edit the channel list.
The manual for the TV is available at retrevo: http://www.retrevo.com/support/Panasonic-CT-27SL13-TVs-manual/id/275ag210/t/2/
. You will need to enter a code to access the manual. See page 5 of the manual for the input connections (page 7 of the PDF).