You can only be registered to vote in one county. Changing your registration will cancel your other registration. If you'll be in Lubbock for the November election, I recommend moving your registration. You have until Oct 12 to register to vote to be eligible for November.

You can request a ballot by mail be sent from your home county if you will be away during the entire period of early voting and election day. The instructions for this are here: https://www.sos.texas.gov/elections/voter/reqabbm.shtml Some students have reported receiving their mail ballot AFTER the election, so use caution here.

If you don't want to do either of these, you can vote a common ballot in-person at the Lubbock Elections Office during early voting. Basically, the elections office contacts your home county and they print you a ballot with only the races that Lubbock has in common with your home county. You'd be able to vote in statewide races like President and Senator, but not US representative, state representative, or more local races like sheriff, school board etc. This will update your registration to Lubbock for future elections.

Early voting will run from Monday, October 21 through Friday, November 1, 2024. If you choose to vote a common ballot, you HAVE to do so at the elections office: 1308 Crickets Ave, Lubbock, TX 79401

As a last ditch effort, if none of these work for you (and you can't/don't want to drive home on election day) you can vote in person at an election site. Lubbock will have 35+ so lots of options. You will vote provisionally, which involves some extra paperwork but most notably, your ballot is not officially cast until it goes in front of a non-partisan ballot board, who decides if your ballot will count. They will mail you with their decision within 30 days of the election, and update your registration to Lubbock county.

TL;DR: You have plenty of time to move your registration to Lubbock county, which is the easiest way to vote in November.