Usually to get apt you need to launch Cydia. If you only have an ssh connection in and would like apt you can go to http://apt.saurik.com/debs/ and grab berkeleydb_4.6.21-5_iphoneos-arm.deb and apt7_0.7.25.3-8_iphoneos-arm.deb. Scp them over and run dpkg -i apt7_0.7.25.3-8_iphoneos-arm.deb then dpkg -i berkeleydb_4.6.21-5_iphoneos-arm.deb. There you go. You can apt-get all of the things now.