Okay well most of these experiences are way back when, but for the most part, these entheogens are pretty harmless (and also pretty weak effects) which I guess would make them good starters. Consider this solely my opinion:
Kratom - Way too expensive for what you get. If you buy just the leaf, not the extract, and spoon it into your meals, maybe worth it. Honestly though, it's a big hassle for what's basically a vicodin. If anything I would take poppy seed tea over kratom, even then I'm not that big on opiates. That being said, if you grow your own kratom, is a much better way to maintain a supply of cheap legal opiates. I'd rate it 1.5-2 stars depending on potency (out of 5).
Kanna - A natural SSRI (pretty much agreed upon). In my experience extracts are relatively cheap and pretty effective for slight mood alterations (we're talking happy-go-lucky day, not the walls melting). Also pretty good for treating mild depression and anxiety. Word of Warning: DO NOT MIX WITH MAOI's such as syrian rue, st. john's wart or kava kava. 2.5 stars.
Blue Lotus - Okay results. Don't expect much. Have drank the wine (and felt the wine), and smoked extracts. Extract was okay, take enough and you get this slight glow around objects, almost cartoonish. Okay starter entheogen, but better if you use along with Kanna extract for more potentiation. 2 stars.
Kava Kava - Definitely a good place to start. In pill form typically very easy to find, same goes for the roots. A kind of a twist on alcohol, and also in high doses and with long-term use may cause liver damage. That being said, a good place to start with something that gives decent effects. 3 stars.
Marijuana - A fantastic entheogen with excellent results, causing very few ill effects, and presenting a terrific myriad of positives for the starting psychonaut. Also leads goes great with any of the above, or all by itself. If you ever get bored, a whole catalogue of different strains can give you different effects. 4.2 stars.
Honestly, most anything that websites can sell to you is typically not worth money. The few exceptions being salvia, mescaline producing cacti and LSA. Last one I can think of off the top of my head is Amanita Muscaria's but I don't really have any experience with those. Hope that helps, and the nifty stars metric does not take into account any strong psychedelics.... lol throw shrooms in there and everything but pot get's a .5 tops...