Though the newest 2017 model 13 and 15" Inspirons will take active pens, the 17" is a touch screen only - you can use a generic capacitive stylus (see example below) -- but not an active pen that works with pressure-sensitive digitizers -- which the 17" model does not have.
Please provide the exact model 7000 system that you have. Dell has many 7000 series laptops.
Below is a list of systems that the Dell Active Pen PN338M Works with.
Starlord models come with both pen-enabled and non-pen-enabled panels. Only Starlord models that have the label "Support Active Pen" support the stylus.
Inspiron 7378 Starlord B 13 KBL-U
Inspiron 7579 Starlord B 15 KBL-U
"Just ordered" likely means the new 8th generation CPU models -- I don't see any mention made of active pen support on these.
The 15-7000 series 2-in-ones do mention pen support -- and the prices are so close to those of the 17" models, it's my strong suspicion there's no way the 17" ones have a digitizing screen on them.
If you look on the page where you purchased the unit, down in the description there may be an accessories section. If a PEN is recommended it should be there.
Giving a Model number as Inspiron 17 7000 does not give much information about the system. My Inspiron 17 7779 2-in-1 does not use an active pen.