A micro USB to USB charger. I plugged it into my computer. I also tried using it with a 5v wall outlet adapter.
1) A ('phone) charger is not the same as a power supply in that, whilst one may be marked, say, 5V 2A, there's no guarantee that it can provide both at the same time ie. at currents >1A many such devices' voltage falls below the minimum recommended (low voltage threshold) of ~4.6V for a pi (esp. a P3B)
2) Most (USB 2.0) ports on a computer can only supply ~500mA (AIUI USB 3.0 ports can supply a higher current but probably will not be switched into that mode by the lead connecting such to a pi.
3) It depends what you mean by a "5V wall outlet adapter" (and, maybe, where you are) - mains sockets with USB charging ports (or similar, pass-through, adapters) are becoming more common, but are, in essence, chargers rather than power supplies (see 1).
W.r.t. to NOOBS' config.txt
, IIRC the NOOBS installer does not normally require/use one itself but, as has already been mentioned, provides a built-in editor to edit those it creates for the O.S.'s it installs. It's default video modes are selected by pressing/toggling a numeric key (1, 2, 3, or 4) during (first) boot, and one of those is a "low-res" HDMI mode which should be supported by most, if not all, current HDMI-to-VGA active converters (HDMI-to-VGA cable
adapters are not
active devices and will not work). If "toggling" an appropriate numeric key does not work (historically this has been an issue with some wireless keyboards not being detected properly) then either, if you can, try a different keyboard, or, with a simple editor (notepad+, nano) try creating a config.txt
on the first, FAT32 partition of the uSDHC card. NB. on most Windows computers this will be the only visible partition.
Still running Raspbian Jessie or Stretch on some older Pi's (an A, B1, 2xB2, B+, P2B, 3xP0, P0W, 2xP3A+, P3B+, P3B, B+, and a A+) but Buster on the P4B's. See: https://www.cpmspectrepi.uk/raspberry_pi/raspiidx.htm