To search in Vim, you need to type the / followed by the character or set of characters you want to search for. The cursor will be in the first character of the search result. Search is case sensitive.
To search forward, press m. To go back, M.
Type :set incsearch for incremental search.
Type :set ignorecase to ignore case sensitivity in search.
Type :set hlsearch to highlight search results.
You can use /.[aeiou] to search for any character followed by vowel, for example. The . denotes “anything”.