I have a 70D also with your same 35 - 135mm "kit" lens. I like it. But I also have a few of the lens, that the others have recommended here in this thread.
I have the Canon 10 - 18mm lens, and I really like it. It was cheap when I bought it two years ago for 200 euros. Now I think they are around 280 euros. I would really recommend this lens for those super wide angle shots.
I also have the Canon 50mm 1.8 STM lens. It was dirt cheap at something like 100 euros off of Amazon.de. Also bought it two years ago. I hardly use it.
And I have the 24mm f2.8 STM lens, this lens I really have not used very much.
I always hear everyone RAVES about Sigma's 24-70mm F1.8. Its not cheap, but I think it might be perfect for what you need.
Btw... I really like Tony & Chelsea Northrup's YT channel.