I am interested in reading agamas or books to learn about the history of the universe and maybe Earth. I am reading Saman Suttam, which is the only non-sectarian Jain Dharma text I know of. If older non-sectarian philosophical ones exist I would be interested. I am also interested in learning what agamas are sort of like the Vedas and give a history of the universe, but I have a lot of reading so only want to read non-sectarian texts for now.

After that if I like it I would consider reading the main philosophical text(s) of whatever sect fits me best. I think Jain Dharma has the highest ethics... it seemed to have developed in unison with Sanatana Dharma and is a unique version of eternal philosophy... if you call it eternal: I do not know. It also seemed to equally or moreso influence Buddhism.