Should there be a specific link between the characters height as well as the tile size for the tile maps? That is if a tile is 32x32 does that mean that a character sprite has to be the same size? Also does the size of tiles I use have any great impact on the game itself?
Your characters do not have to be the same size as the tiles, but you need to keep in mind that they need to align on the same axis. For example, if you make your sprite 64x64 then you need to align them between two tiles rather than one. It's all about how you want to design your tile system. My way is not the only way about doing it as well, others may prefer to keep their characters aligned a completely different way. My way is just an example about how you can go about doing it. Also, sprites being the same size as your tile size makes it easier to program, and you don't have to worry about your sprite being mutilated by tiles that render above the character.
The size of tiles is mostly based on preference of what you want the game to feel like, but it does also affect the performance of the game you are making. The bigger the tiles are, the more the below items are increased.
The smaller the tiles you use, the slower the game will be. You need to find a suitable size for your tiles, that gives you the flexibility you want while keeping the game running good.