I can't see your Crucible Rep, so I can't tell if your Rep is high enough. You have the New Monarchy mark equipped, so any Rep that you get is going towards your Clan and not Vanguard/Crucible Rep. I'm not sure if you get marks if your Crucible Rep is too low, but I honestly have no idea (just a stab in the dark) Also, you can not get more than 100 marks per week, and I'm not sure if you can obtain more than 200 at a time. Shards can be obtained through a number of different methods. Public events at Gold Tier... Weekly Strikes... (I just got 7 shards for completing the Weekly Nightfall Strike) But you'll only get one reward per week on those. If you can earn enough marks to buy Legendary gear, you can also dismantle it for a chance at shards. I believe you also have a chance at getting shards from running the Vanguard strike list at certain levels. Check the "rewards" section of the description of the various strike levels.

Crucible Marks are obtained in the Crucible, not PVE.

Crucible marks are earned by playing pvp in the crucible. Vanguard marks are earned for lv 20+ vanguard strike playlists, daily/weekly heroic missions (first time per day/week), public events, and material trade in.