As far as I know, ANKI is not especially good for that, but here are some thoughts: You can choose to add cards in the order they were created or randomly. If those options aren’t useful, you can use the desktop program to select all cards and “suspend” them. When you want to add specific cards, simply search for them and unsuspend them manually. Honestly, though, I would just get a deck in frequency order, suspend all the cards that you already know or where the translation is completamente transparente, and go through the first thousand in one month (maybe 30 minutes a day).

One more thing: Since English and Spanish are closely related, you really don’t need to rely too heavily on flashcards at all. Start watching youtube videos — that will help get your pronunciation under control before you’ve learned 10000 words with the wrong pronunciation… much easier that way. Much.