Hi @FulsomeSmile475 and welcome to the forums 
In addition to what @Ariana2022UK said above, there are a few more suggestions:
-
Default training missions: Have a look at the three [OFFICIAL] Twitch Flying Lessons in Community Content Hangar > Community Guides.
-
Top 10 of mods: @Baracus250 has made a couple of spreadsheets listing these:
and
-
Is there a specific program that i need to download and install to manage the various MODS i wish to apply? Addons Linker is a popular choice, and can be downloaded for free from the Flightsim.to website.
-
Please advise of any MS Clans willing to take a new pilot? I suggest looking in Community Content Hangar > Friends, Clubs & Groups. Virtually all groups are very happy to see new pilots! You can also join one of the scheduled multiplayer flights shown in the Community Content Hangar > Community Events calender.
-
Lastly, I have installed MS Flight via my Xbox acc. is this ok, or am i better purchasing and installing the game via Microsoft for MOD compatibility etc…
For PCs, MSFS works exactly the same irrespective of whether you purchased from the Microsoft Store or Steam, or installed using the Xbox App or Microsoft Store (which appears no longer to be possible, according to some reports). As @Ariana2022UK says, this won’t affect your ability to add mods & add ons.
Hope this helps!