I can recommend the UCSB SRA program:
https://www.summer.ucsb.edu/programs/summer-research-academies/research-tracks
It is for 1st time high school researchers. My daughter did the astrophysics track and it was a great experience. I believe that it is a competitive admit, but not as competitive as SIP (below) or COSMOS (recommended above)–but I could be wrong about that.
Once you have a year of research experience you would be eligible for UCSC SIP:
https://sip.ucsc.edu/
And there is SSP, which is insanely competitive to get into:
https://summerscience.org/
But if you do get in … you are set for college. This program is co-sponsored by Cal Tech, MIT and Harvey Mudd. I am pretty sure it is easrier to get into those colleges than this summer program (which offers great financial aid).