Don’t know about getting the aircraft to “hold” at selected points (sure there is a way but ATM I don’t know - suppose you could just pause the game and use the drone camera to have a look around) but sightseeing tours are quite easy to set up. In the start screen select a starting and finishing airfield then, in the order you want to visit, click on a point in the map and select “Add to Plan”. The sim will create a waypoint and adjust the plan to include it. Repeat for however many points you want then go fly (after selecting a suitable aircraft and weather of course).
I use the G1000 and autopilot to fly the aircraft whilst I look at the scenery!
Little Navmap is a flight planning programme that easily integrates with MSF and allows you to do the above but, IMO, is easier although the programme itself does take a bit of learning - well worth it though as it’s one of the best flight planning utilities around and is very popular (and free!)
There are lots of flightplans already done and published on this and other forums, many have been made with LNM or similar, and can be loaded into MSF to do what you’re looking for. Have a look at flightsim.to website which carries a good selection as well as being the “goto” place for 3rd party addons.