I think the "rooted to the spot or they die" thing would be about the first thing that would be addressed by technology. As soon as the first tree thinks to collect its seeds into pots so it can move them around to catch the best light, the saplings are mobile.
Then placing the pots onto a sled covered in loam lets the tree move around on its own. The invention of the wheel and carts just makes this easier.
With or without carts, the differences between their technological advancement and ours will be notable, however. I've written the following assuming trees that can see, and have put their seedlings in carts.
They will have FAR lower energy. A human could not live on photosynthesis. This means they must move far less, and likely have far greater reaction times. This would slow progress. However, they live longer, so would get about as much done in a lifetime.
They are considerably more flammable than us, and with slower movement and reaction times, fire would be very dangerous. Fire, and hence pottery and metallurgy, would be slower technologies to develop. Agriculture and all our food-related technologies would no longer be primary concerns.
Herbivores would be seen as predators and would be fended off with simple spears, and perhaps by encouraging and protecting predators. Domestication of animals could also happen with those tree-living animals that don't harm the tree (squirrels, birds) and perhaps they might perform symbiotic cleaning and nutritional services. But the main drive to animal husbandry for food wouldn't be there, though as beasts of burden for transport, it might still happen.
Building walls might be useful for protection, but roofs, stairs, multi-storey buildings etc would be largely unknown since they would block light.
Transport would be a main driver, since they don't have legs. Cart tech and road manufacture would advance quickly. Roads would initially have to be very gently sloped, with switchbacks for any serious hills, but they'd get better fast.
Water travel would need to be done carefully, perhaps with ferry-like ropes running the length of each river, to control speed down to the reaction times of the trees.
Transport accidents could/would leave people rooted to the spot where they crashed, so technology would advance to be able to transplant root-balls without killing the tree, as a matter of emergency healthcare.
Healthcare would involve things like mold, parasites and infestations; re-splicing broken limbs, sealing the stumps of severed ones, etc.
The main cause for wars would be horizontal space, and areas with good sun - so wars would likely happen, perhaps even more than with humans, and would likely involve fire as the main weapon, rather than bladed or explosive things. Though they would also use the tools they use for harvesting non-sentient trees, and the damage you could do with a mere rope trap to sweep people off their carts could be deadly. While they'd be far more stable than people, once they were down, they'd be down.
Cloth would not be needed for coverings, and such light-blocking things would not be seen as useful.
Simple machines - wheels, levers, etc - would still be invented, but an industrial revolution perhaps needs a requirement for things like cloth. Rope might be a necessary-enough thing to be worth making machines for. Also carts, of course.
The theoretical max for Photosynthetic efficiency is around 11%, but plants typically attain only 3-6%. Improving this would be one of their technological focuses. Taking energy from the sun might eventually be supplemented or even supplanted by injections of sugars.
Cosmetics could include, as well as human style clothing, jewelry and cosmetic nesting animals, cosmetic splices from nonsentient flowering trees, etc.
If the trees can't see, that'll add a whole new dimension to the differences.
The concerns covered by Maslow's hierarchy of needs may be worth going through, to figure out what the main concern of the trees would be at the base of the pyramid, and how that would drive their initial research, then the concerns higher up the pyramid as they grew in technology.