I usually buy my hemp Twine from Walmart or Michaels Arts and Crafts. There’s also a store in my location that sells a lot of music and weed related items and they sell tons of hemp twine and glass pendants. I’d say look around in your area for craft and bead stores – there’s bound to be a store that sells hemp close to you.
Same with wooden beads – I bought nice ones from Walmart. You can also look at local dollar stores and thrift stores – look for not only bags of beads, but necklaces, too. At the dollar stores in my area, they sell a few wooden beaded necklaces and I take them apart and use those beads for hemp necklaces. Same with Thrift stores – I’ve bought my nicest wooden beads (and beads in general) from necklaces I took apart from thrift stores. Just last night I bought an very long necklace with a little over 100 coloured wooden beads for only a dollar!
I’ve bought second hand hemp necklaces at thrift stores with gorgeous glass charms and pendants for 1 or 2 dollars each from thrift stores, too! I go to thirft stores looking for materials a couple times each week – sometimes you find a ton of necklaces to buy, sometimes you walk out with nothing. You need to keep going to find something, but when you do it’s always well worth it.

Another idea is to make homemade beads with bakeable polymer clay. They’re very easy to make, and you can make endless amounts of designs!

Glass pendants and charms are the hardest things to come by for me, and especially at affordable prices! I’ve never really bought anything online, so I can’t give much advice to you about that, but I’ve looked at ebay.com in the past and they have some on there sometimes for very cheap. I wish I could help you with online buys, but I’m not experienced and don’t know what sites are reliable and which ones aren’t.

Something I use as pendants, and people love and think is cool, are guitar picks. They’re very affordable and you should be able to buy some from any music stores that sell guitars. The more popular ones are the ones with special pictures or designs on them – I’ve bought some beatles-themed guitar picks, and they sell the best. Skulls and some psychedellic-like things are also popular. If you have plain ones, what’s fun to do is to attach some metal charm to it – like if you can find music notes or something cute, it looks pretty nice.