If I have 128x128 texture, and the picture for this texture will be like 1024x1024, will it be more quality?

It will be resized to 128x128. If you want better quality, buy 256x256 or 512x512

No, it will be less. Converting 1024->128 would instinctively be something like 1/64th of the quality, however the compression itself will result in degradation too, so you can expect that using a 1024x1024 texture in a 128x128 slot will be approximately 1/200th of the quality.