Here you'll find a lot of useful stuff:https://www.reddit.com/r/antkeeping/com ... ful_links/
The best beginner species you can get (in my opinion) is Formica fusca. They are quite large (not as small as Lasius or Tetramorium), relatively timid (also not known as escape artists, unlike large Lasius niger colonies that can seriously tackle your barriers), grow reasonably fast, very active during the day
(many ants are night owls, Formica fusca is the opposite) and their colonies don't reach the massive size some Camponotus (10000+) or Lasius (L. niger 50000, L. flavus 250000, L. fuliginosus 2 mill.) do. Oh, and they don't murder your other ant colonies should they ever manage to breach your barrier (unlike Lasius niger which are EXTREMELY territorial and hostile towards other ants).
Formica fusca usually tops out at around 5-6000 workers no matter how many queens the colony has (they are one of the more rare species that can have more than one, although that only happens if they found together, they will usually not accept additional queens later on) which keeps even "adult" colonies very manageable. They don't need huge amounts of nesting space although they definitely need more than one outworld and some meters of tubing as they are very active ants that love to walk around.
- If you want/need to go cheap:
Airtight plastic containers can be obtained for a few bucks at the dollar/1€ store (mine did cost 5€/piece). Just drill a few dozen small holes into the lid, apply a barrier (Fluon, or baby powder mixed with rubbing alcohol) to the sides of the container (a 2cm stripe at the top is usually enough) and the lid (around the ventilation holes) and you're ready to go.
As a substrate you can use grout or sand-clay mix (2-5€), a few cleaned-out snail houses make good decoration and a bit of sand (reptile sand works well). Test tubes are fine as nesting space, ants are fully capable of modifying them to their needs (they will just carry some sand into them and plug it wherever they want), you can use cotton and drinking straws to make the entrance area smaller (prevents evaporation and makes the water tank last longer). A small piece of paper folded in the middle makes a nice tent-like cover that keeps the nest dark and is easy to take off if you want to have a look at them.
If you want to plan for the future get some vinyl tubing (1-2€ per meter), make a big hole into the smaller side of the container (the hole must be smaller than the vinyl tubing!) then press the tubing threw (if it doesn't work hold it under hot water for a few seconds) and plug the tubing's end it with cotton. Now you can add a new container whenever you like.
- If you want to spend more money... well, there are a lot of ant shops out there that sell formicaria and outworlds.