I like the Halo universe, so I play everything that has it name on it.
I almost forget what the first installment was about, however, this one looks really good in term of adding an expanded story to the Halo universe and preparing for Halo Infinitive.
The game involves around 12 missions. All can be beaten in around 8-9 hours. In Normal difficulty is well enough to have proper challenge and you can almost no frustration (in my case, I do not like to spend 30 minutes and waste it), in this case you can save the game often, so in case you can go back you just load the saved game.
Each mission has its own strategy, something I like very much.
My recommendation is to try the tutorial first (basic and advance), it will facilitate and reduce the learning curve. The better you play the more you get out of the mission.
This game has a multiplayer, I tried it just one but no one connected (I just wait 20 second), so it is not a measure. I am pretty sure that a lot of players will be found if wait enough time.
Try it. Really good game.