How to disable Lantern from startup?
You should be able to do it from UI.

Click on settings icon on the bottom right of lantern browser window:



You can disable auto-startup there.

If that doesn't work, try the following:

Try setting autolaunch to false in lantern config

~/Library/Application\ Support/Lantern/lantern-2.0.10.yaml

version: 3
cloudconfig: http://config.getiantem.org/cloud.yaml.gz
cloudconfigca: ""
addr: 127.0.0.1:8787
role: client
instanceid: 9b965155-2908-4292-b379-69f968f890f1
cpuprofile: ""
memprofile: ""
uiaddr: 127.0.0.1:16823
autoreport: true
autolaunch: true
stats:
  reportingperiod: "0"
  statshubaddr: pure-journey-3547.herokuapp.com
server:
  unencrypted: false
  country: ""
  registerat: ""
  portmap: 0
  frontfqdns: {}
  waddelladdr: ""