Beginner Q: Hexa tiles look strange, overlap, should I start with Documentation?

Hello,
I am new to game development and with a programmer I am creating hexagonal turn based game.

While creating the map I choosed “Hexagonal” and 201x176p width and height. Why? Because I used in paint.net a plug to draw a hexagon. Should I use a power of two number like 64x64, 128x128?
My problem:

hex

The hexagon tiles looks strange, they overlap, how can I fix it? In the left you see how I would like to have them ingame.

Second Q:
Should stop with working on this project and read documentation first?

Thanks in advance.

Please play around with the “Tile Side Length (Hex)” in the Map Properties, until the tiles align properly.

Indeed the documentation is still lacking in this area.

Put “Tile Side Length (Hex)” from 0 to 100 and changed “Stagger Axis” from Y to X and it looks good now.
Allow me one question: Should hexagons have some special size? Like power of 2 (64x64, 128x128), because I have 201x176p and I am not sure if I will have problems with it later.

No, that should not be necessary. If you can make the tiles align properly in Tiled then you should be able to do the same thing in your game.