Samsung builds two models of the Galaxy Note8. Once with Samsung Exynos for the EMEA regions and once with Qualcomm Snapdragon 835 for the USA and China regions.
The model you mentioned, SM-N950U, runs with Qualcomm Snapdragon - and is therefore neither supported by LineageOS nor LightROM or /e/ OS, because these “Best ROMs for Galaxy Note8” all work with the Exynos 8895 chipset.
For the Samsung Note 8 “greatlte” with Exynos chipset, /e/ OS 9-Pie is in planning.
There are several tutorials about /e/ OS image building in the /e/ forum .For example:
→ [HOWTO] Build /e/
→ [HOWTO] Build /e/ without docker
→ [HOWTO] build eOS in old fashioned way with breakfast -- now with interactive script)