First, welcome to AA. I'm currently working on the second 29 gallon tank I've owned. I'm planning tetras and corys. I use Aqadvisor to help plan my stocking. I just got 7 X-ray pristella tetras and plan to get 7 rummy nose tetras. (I actually have one, I had a columnaris disaster with one survivor). I'm going to get 6 corys. I've since learned that rummys as well as cardinals and neons are not good new tank fish. I've had better luck with cardinals than with neons. IMO
neons have been overbred. I've found glow light tetras to be very easy to keep. And of course the pristella tetras I currently have are wonderful beginner fish. There are so many great tetras. See what's in your LFS
and start planning your stocking around them. Do double check on their needs. You can keep most tetras in pH up to 8 if you are not breeding. Bueno Aires tetras are nice fish but can be nippy and do eat plants so if you are doing plants they are not a good choice and definitely not with angelfish. In any case, my favorite tetra at any given time, is the school I have in my tank. You really can't go wrong with one larger or two smaller tetra schools in a 29 gal
tank. I can't help you with the clams. I'd be more inclined to add a golden mystery snail. You don't say what kind of Pleco. A common will outgrow that tank. Make sure you have real driftwood for your Pleco. I love the bristlenoses which stay smaller, but they don't fit in with my current stocking plan. Best wishes on it.