You can use the advanced search features on some sites. Narrow your search by type of plant, cost, flowering time, difficulty to grow, etc, to suit your grow environment and experience.
Once you have entered your parameters, it will be a little easier and less overwhelming to select a plant to start with.
I would go for a classic. Something tried and true, with little variation and a sturdy, easy to grow plant.
Like an AK47 or Northern lights.
I am not recommending these in particular, just an example.