From Longman Dictionary of Contemporary Englishget to/reach first baseget to/reach first baseSUCCEED IN DOING something a) American English informal to reach the first stage of success in an attempt to achieve something You’ve gotten to first base if you’ve landed an interview. b) old-fashioned informal to kiss someone in a sexual way, used especially by young men to talk about the first stage in a sexual relationship → first base
Examples from the Corpus
get to/reach first base• Compared to this little middle-aged lot, we didn't get to first base! 