It depends on what you think you might want to do. There are a few things to consider. The first I would say is portability. If you think you will be taking it out places then not too big. But, big is usually really expensive so that might exclude a first scope.
The next is power. There are two parts to a telescope, the aperture (fat end of the scope) and the eyepiece. The aperture gathers light. The bigger aperture, the dimmer, more distant objects you can find. It is the eyepiece that gives you magnification. Generally go for the biggest aperture you can afford.
However the other thing to think about is the mount. There are two. The first and cheapest is an altz-az mount. These are really easy to use and are great for getting started. Basically they allow the telescope to move left to right and up and down. If you want to look at something in the sky, then move it up, dead easy. However the sky moves, and once you start looking at it through a scope, surprisingly fast. It doesn’t move left to right, it moves round in an arc as the earth spins, so a little harder to control. If you want to look at something for a long time then you want an equatorial or eq mount, like the one you posted. This is also what you want if you think you want to do long exposure astrophotography, for nebula and the like.
If you do want to do astrophotography then a motorised mount is a must. These attempt to keep the target on track. An altz motorised mount can keep on track for about a minute and are great for the moon and planets, but if you want to capture nebula, galaxies and star clusters, an eq mount is better. Most now have a goto function where you put in what you want to see and your scope tracks round and shows you it. Personally I like that, but some say you never get to know the night sky and never learn star hopping.
Celestron and Skywatcher are two of the best makes. If it was me, I’d go for the biggest Celestron motorised Eq mount I could afford, but probably give Skywatcher a very serious consideration. If I couldn’t afford anything decent then look at a motorised altz mount (what I have). But although I bought an altz to get started, my most recent purchase was an eq mount for a small scope and camera. That needed its own sturdy tripod and came to a similar cost to the scope. It has been a learning exercise but if I turned back the clock I’d have spent it on one setup.
Do you have a rough idea of what you want to do, see and what your budget is?
