Ok, be low there is a lock to unlock when reach level 32 then will have more space.
Max to L30 
, When you farm, those parts will show up in different stages. Those there, are basic modules that can reach maximum level of L30. The gray edged are the common parts and will need transformation to RARE "blue edge corners" and the blue ones will need to go to purple transformation to get the L30 spot as you have the blue torso. There is no more remedy than to max them for now. When you farm, try to observe carefully for those parts and do not eat everything to level up a part. Need to check what can help for now.
The one in the center can go from L1 to L40 as it is. Do not enhance beyond L40 for now. 
The other 2 go for L30 unless you farm and get shield in the rare state then from rare transform to epic.
Below there is not much remedy than to go to L30with the side weapons. The top weapon can go to L40. That will help a lot to pass campaign few more.
In resume, farm in a place you can use auto farming. Ok to farm in step 3 if auto farm work. Gold it is not super or XP but I can see that side fights will be too strong for extra fuel and XP. Ok to farm there for now until get more gold and possibility of 0-1 box to level up or use as weapon .
You need drone L30 that red one for now. Will help
That weapon maybe soon will be useful. just the current set up for close combat won't be that good but maybe for campaign can help. It can go to L40 if go for it in the sideline.
