You can hide/change the tabs at the top of godot to remove the 3D/Asset tabs:
Editor > Manage editor features.

importing pixelart

1. Under the import tab uncheck filter.
2. Change preset to 2D pixel, set as default.
3. Reimport any previously imported sprites.

window view sizing

1. Open project settings.
2. Display > Window (Width 320 x Height 180 is nice.)
3. Test Width & Height are the onscreen size (Width 1920 x 1080 is nice.)
4. Under Stretch set the mode to 2d. Set aspect ratio to keep.

player animations

1. Create your player node (maybe KinematicBody2D)
2. Create a Sprite sub-node. Drag and drop sprite onto "Texture".
3. Under animation, set the number of hframes (cycle through frames to check.)