Ok here is a screen shot and I don't understand why this unit can not go further to the right when he has enough action points.
1. As others have said, the first thing is that you are in swamps so MPs are expensive, especially for motorized units like the SS one on top.
Every time you select (or mouse over?) a hex, its designation is somewhere at the top of the page. I suggest you take a little time at least to figure out what terrain is what.
Really I suggest you spend an hour or so at east to skim through parts of the manual. You don't need depth of knowledge to play, but you do need some basics. I'd highly recommend having the manual open on your pc and flicking to it frequently as you are figuring out the very basics.
2. The second thing is that you are crossing a river to go forward. That costs more MP (at least its not a contested river crossing, those cost even more!)
3. The third thing is that you have 3 units selected (outlined in purple). They belong to at least 2 different corps (because two different HQs are outlined in orange )= higher HQ of at least one unit selected) and it looks like infantry divisions from 1 corps as well as the Panzer and Cav divisions from another corps are outlined in yellow (= units sharing an HQ with a selected unit). So it seems that under that SS Motorised Divsion you have selected you also have at least 1 Infantry Division from another Corps selected.
The areas highlighted that you can move to are only highlighted when ALL the units you have selected can move there. So one slower unit will restrict the apparent range of the group. However if you move the group there, some units map still have (many, possibly, though not so much in swamps!) MP left to keep moving.
Note: To select a single unit you use the box on the right hand side with the three unit counters displayed in it and click inside the unit counters to turn them on and off individually for selection purposes. EG to move just the SS division you click the hex to select all three like you have, then in the right hand box click on the other two to deselect them, leaving you with just the SS unit selected. You'll likely see a big change in the apparently available movement immediately!
4. Yes, there may well be enemy units out of sight blocking movement forward. If your selected unit(s) moved forward 2 hexes they may well find enemy units blocking them. Even if these enemy units are non-combat units (like HQs, Airbases or routed units) that will automatically relocate away and free up the space to be moved into, that space will not initially appear to be free to be moved into.