Most garden weeds require a lot of sunlight. You'd either need a full sun location or plenty of grow lights.
The soil needs to be reasonably moist because uprooting most plants shocks them badly and their roots will need a lot of care and support for a week or two.
To help the plant acclimate you can also put a plastic bag loosely over it (assuming it's in a temperature-controlled area) to retain humidity, and gradually remove the bag. Of course, if it's in full sun and the bag is on too tightly, you will steam your plant to death.
Here's someone's set-up for cultivating aphids:
http://www.tracyhicks.com/aphid.htm
Oh, also aphids are sometimes fairly plant-specific. So if you get a certain plant, make sure it already has aphids on it so you know you have the right variety.
Edited by OhNoNotAgain, July 19 2020 - 2:59 PM.
Past & Present
Veromessor pergandei, andrei, stoddardi; Novomessor cockerelli
Camponotus fragilis, Camponotus sansabeanus (inactive), vicinus, laevigatus/quercicola, CA02
Pogonomyrmex subnitidus, P. californicus (inactive)
Liometopum occidentale (inactive); Prenolepis imparis; Myrmecocystus mexicanus (inactive); Tetramorium sp. (inactive); Lasius sp.
Termites: Zootermopsis angusticollis, and a box of drywood termites that can't be seen
Isopods: (most no longer keeping) A. gestroi, granulatum, kluugi, maculatum, vulgare; C. murina; P. hoffmannseggi, P. haasi, P. ornatus; V. parvus, P. pruinosus, T. tomentosa
Spoods: (no longer keeping) Phidippus sp., other