1. 'Not only' at beginning of the sentence requires an inversion of subject and verb. The verb, or auxiliary verb if necessary comes immediately after 'Not only'
Not only is he intelligent, but he also....
Not only can he speak 5 languages, but he also...
Not only did he win first prize, but he also ...
2. The sequence 'Not only... but also' is a correct, standard and common construction.
Learn it and practise it!