Hi,
Your Viewsonic monitor is unlikely to work with your A2000... Like most Amigas, the A2K uses slow 15KHz screenmodes and require either a dedicated monitor (like the 108x series) or an expensive multisync-capable devide.
An alternative is to use a scan-doubler (which effectively de-interlaces the Amiga's output and ups the screen scan rates to VGA standards), but these are usually horrendously expensive.
If you can't get the Amiga to 108x cable, try and get hold of an A520 video modulator. This will generate composite video (and RF) output from your Amiga. Not the best in terms of quality, but these are usually dirt cheap and can be used with pretty much any television.
- Ali
P.S. Welcome to Amiga.org!