1) BasicPawn should work out-of-the-box. As long your source is in the same folder with compiler and include folder. If you want to set everything up manualy, you have to create your own configs.
Go:
Tools > Settings & Configs > Configs
2) You can find
High contrast mode in the settings under the tab TextEditor.
If you dont like how the syntax color looks you can download custom syntax highlighting files
here.
Go:
Tools > Settings & Configs > Settings > TextEditor