Quote:I am new to GIMP....snip... i have already drawn the outline of the text with Autocad in vector format.
Looking at 'not snags' but common beginner issues.
For a poster and if it going to be printed. If yes, make sure it is as suitable size and 300 ppi. Start off with one of the Gimp presets say, A3 to see the sort of size required. Do not come back saying my poster size, 300 pixels x 500 pixels, @ 72 ppi is blurred when printed.
Using AutoCad for a vector (svg?) is fine (providing Gimp will import it) You can go via inkscape: dxf -> svg.
You can either import File -> Open as Layers as a graphic or directly into the paths dialog, right click in the paths dialogue.
This a quick zip round using LibreCAD exported as a SVG and the text comes in as separate paths. You can leave them or you can merge them. example: https://i.imgur.com/mi4hjOA.jpg
Bound to come into Gimp either too small or too large. Using the scale tool, make sure the mode is for paths and link height & width together: https://i.imgur.com/GCjYnVt.jpg
Use as many layer as required, more is better than fewer. A quick example: https://i.imgur.com/eSalTDC.jpg