PCIE slots are backwards-compatible, so you can run a modern card in a 2.0 slot. Only with the very high-end cards are you seeing older PCIE slots starting to run short on bandwidth, which ought to not be a problem for a 1050ti.
As for the RAM, the motherboard doesn't need to support the RAM, only the GPU needs to.
The biggest questions are different ones than you asked. What is your exact power supply? What is your motherboard? What is your CPU? The first is always a question for any GPU upgrade. The second because of you have a very old motherboard, sometimes ones with an older BIOS, especially with prebuilts, have trouble with modern GPUs. And the last because it's good to make sure your CPU is good enough to take advantage...