Buffalo Schools in NY have some fantastic free resources!
Common Core Grade Level Expectations
Common Core Workbooks by grade
None of these lists below are comprehensive.
They are some of the most popular programs/ curriculums but there are so many to choose from.
These lists will help you get started on your search.
Secular (not religious based)
Blossom and Root (Charlotte Mason inspired)
Build Your Library
Secular Science Curriculum
Jarring Science Club (1st-6th)
Building Foundations of Scientific Understanding (K-8)
Lower Secondary Science (7-8)
Science Matters (9-10)
MPH Science (1-6)
CPO Science (6-12)
Elemental Science (PreK-12)
REAL Science Odyssey (1-9)
Mel Science (6-12th)
Mel Kids (K-5th)
Non- Secular (religious) There are lots more, I truly haven't searched them yet.
The Good and the Beautiful
Social Emotional Learning
Character Lab- Free online resource
Big Life Journal -PDF printable for children as young as 5 to build a growth mindset
MindUp- Low cost age grouped books including science based brain lessons presented clearly and concisely
Boxed Curriculum- contains all that you need
Moving Beyond the Page (PreK-8)
Discovery K12 (K-12)
Global Village School (K-12)
Build Your Library (K-9)