What hormone therapy is best for ER/PR positive breast cancer after lumpectomy?

So updated info. 61 turning 62 end of May. Found 2 sites 6mm 7 mm right breast. ER/PR positive and HER2 negative. I'm having a lumpectomy on May 7 along with sentinel node removal. Suggested treatment if node is clear is radiation 4-12 weeks. 5 days a week the hormone therapy. I've reading on the medication but not sure what's best. If node has cancer then Chemo and radiation