I know the baiscs of building (kinda) but will have someone helping me. can any motherboard support any gpu or do you need those new ones to support it. (going use a gtx 1050 ti).
To answer the original question, as long as the motherboard has a PCIe x16 slot, you can use whatever GPU you want. It doesn't matter if it's PCIe 1.0, 2.0, or 3.0. All the new GPUs are backwards compatible with older PCIe generations.
Whether the BIOS can recognize the GPU is a different story though, but incompatibility is rare.
Post up your current motherboard and maybe someone can verify for sure, but you should be fine.