Another newbie needs help

I have an MZ50 with a Sigma 28-80mm F3.5-5.6 AF lens. I've had it a few years but I'm only starting to get serious about it now. I'd like some advice on what types of secondhand lenses are worth buying either manual or autofocus and I'd like an idea as to what to look out for in terms of compatibility with the MZ50 mount. I've seen loads on eBay but I don't know for sure if any of them would fit and work properly. I'd like a telephoto lens and a wide angle lens. Ideally I'd like a telephoto lens with macro capabilities.

If you stick to SMC Pentax-FA or -F autofocus lenses, you will know that they are compatible and that you are getting the best quality.

Some zooms will go down to a magnification ratio of 1:4 which is 1/4 life size, not bad at all. A proper Macro lens will be a fixed focal length but will go down to 1:2 and maybe even 1:1 Quality of such a Macro will be exemplary!

In manual focus lenses, if you stick to SMC Pentax-A series lenses, again you will have compatibility and there will be no problem with quality.

There are lots of good lenses on eBay of these types, just be careful about the sellers' feedback, the description given and look closely at any photos. And ask questions if you need more info....