Leaning to one side

[LEAZER48]

My48 has been sitting awhile but its ready for the road. I noticed today looking from the front of the body is leaning lower on the driver side, is this a front or rear spring issue, maybe shocks, could use some advice to correct the problem, just thought of another issue not related to the leaning, I purchased a new fuel pump, should it have a filter screen inside the fuel bowl or will a inline filter be ok.
Thanks to all who reply