Honestly, a little portable TV tray can serve as an altar, especially if you can’t place a permanent down for whatever reason, like if you have family or friends that wouldn’t be accepting. You can also use any cup or glass as a Chalice, any knife (even a steak knife) as an Athame. You can be surprisingly discrete if your circumstances and / or simplistic, if your circumstances require it. Just putting it out there. 
Also, please do stop by the introduction thread and tell us a bit about yourself. It’s required as a rule: Introduce Yourself To Members Of The Forum
Glad to have you!