If you press * in the Vim editor it will search for the next place where the word the cursor is over appears. The # key does the same thing, but searches backwards instead. Unfortunately, this only works for one word at a time. But if you add some code to ~/.vimrc then you can extend those functions to work with whatever you have selected when you are in visual mode.

" Search for selected text, forwards or backwards
vnoremap <silent> * :<C-U>
  \let old_reg=getreg('"')<Bar>let old_regtype=getregtype('"')<CR>
  \gvy/<C-R><C-R>=substitute(
  \escape(@", '/\.*$^~['), '\_s\+', '\\_s\\+', 'g')<CR><CR>
  \gV:call setreg('"', old_reg, old_regtype)<CR>
vnoremap <silent> # :<C-U>
  \let old_reg=getreg('"')<Bar>let old_regtype=getregtype('"')<CR>
  \gvy?<C-R><C-R>=substitute(
  \escape(@", '?\.*$^~['), '\_s\+', '\\_s\\+', 'g')<CR><CR>
  \gV:call setreg('"', old_reg, old_regtype)<CR>

After adding this, select some text in visual mode (press v and move the cursor around) and search for what you have selected with * or #.