Tomorite's pretty good, WBMKK, as it has the right balance of nutrients for toms.
If you've just taken on a new plot, then one of the first crops I'd plant is comfrey, and also use the inevitable nettles for a really juicy natural fertiliser. It's fabulous stuff, and also, in our opinion, the right food for leeks, onions and soft fruit.
And the rest of the plot as well...
And free...