Looks like Russia's launching air attacks from the Moldova in the south, Belarus in the north, and Russia itself from the east. Also likely trying to seize the port at Odessa probably to bring in more troops after they gain air superiority.
Fox news reporting the landings have happened in Odessa.
https://twitter.com/user/status/1496692645200113664
Buzzfeed News and CNN reporting Russian units in Belarus have opened fire on Ukrainian border units. Belarus military also reportedly involved.
https://twitter.com/user/status/1496717309163020293
https://twitter.com/user/status/1496718770601340929
CBS correspondent obtains video of tanks crossing Belarus-Ukrainian border
https://twitter.com/user/status/1496719765049511939
Update map of Russian attacks so far
https://twitter.com/user/status/1496712887045439491
Kyiv airport also hit apparently.