iPhone SE 2020 compatibility

Yes. This is from the SE 2020 Specifications, which you can easily see yourself at www.apple.com

Model A2275*

• FDD‑LTE (Bands 1, 2, 3, 4, 5, 7, 8, 12, 13, 14, 17, 18, 19, 20, 25, 26, 29, 30, 66, 71)
• TD‑LTE (Bands 34, 38, 39, 40, 41, 42, 46, 48)
• CDMA EV‑DO Rev. A (800, 1900 MHz)
• UMTS/HSPA+/DC‑HSDPA (850, 900, 1700/2100, 1900, 2100 MHz)
• GSM/EDGE (850, 900, 1800, 1900 MHz)

you're welcome

Yes, if you buy it from Apple and you pay for an unlocked phone, which will require to pay in full up front.