Beto O'Rourke won his primary March 6th in Texas. He faces Ted Cruz (R) in November.

Tim Kaine was uncontested in the June 20th primary in Virginia. He faces Corey Stewart (R) in November.

If you're asking about Bill Nelson in Florida, their primary is 10 weeks before the election, so the end of August. I don't think Nelson has a serious challenger.

Links for tonight below:

New York Primary Election Results
https://www.nytimes.com/interactive/2018/06/26/us/elections/results-new-york-primary-elections.html

Oklahoma Primary Election Results
https://www.nytimes.com/interactive/2018/06/26/us/elections/results-oklahoma-primary-elections.html

Maryland Primary Election Results
https://www.nytimes.com/interactive/2018/06/26/us/elections/results-maryland-primary-elections.html

I hope this was helpful.