The whole of Namibia in 2 weeks is suicide.
If you start in Windhoek I would suggestb the following:
Straight to Swakopmund . There you have choices of camping at Spitzkoppe for 1 night and 3 nights in Swakop (experioence the town, the surrounding desert (Naukluft Park = permit required)).
If so inclined also visit Brandberg (the highest mountain in Namibia and an old extinct vulcano) via Hentiesbay for a day tour. This can be combined with a visit to Cape Cross to visit the very large seal colony in Cape Cross.
Then drive down through the desert from Swakopmund via Naukluft Park vis Solitaire and overnight 2 0r 3 nights in Sossusvlei (Sesriem Canyo and Dead Vlei ), Going to Dead Vlei is a must but allow a full day because it takes just overv 1 hour to reach the destination. Once there and out of the car it takes aniother hour to reach Deadvlei by foot through mostly sand. You can book a ballolon trip in Sossusvlei however it is rather expensive (R 6.000,-per person in July 2017)….BUT if you love the desert at sun-up from above….Totally worthwhile….)
So, BE PREPARED…
From Sossuslei you go southwards through the desert in the direction of Aus. Make sure you take the last stretch on the D707 (beautiful, breathtaking scenery….it is also called the garden route of Namibia) until you hit the Keetmannshoop / Luederitz tar road near Aus.
Camping in Klein Aus is in remaekable scenery. Near by you find the wild horses and remarkable desert scenery. Visit Luederitz for a day to “inhale” the old german colonial times and if time permits, visit the cemetry just outside Luederitz off the tar road. It depicte the historic happenings during the tej anglo boer war,gthe diamond times , the first weaorld war… quite interesting. In Luederitz several commercial desert excursions are
offered and so also in the Bahnhof Hotel in Aus (sundowner tour onto the high mountain with a 4×4 as well as a Sperrgebiet tour. I can recommend both.
From there drive southwards to Keetmannshoop and stay one night at the Kookerboom Forest which is quite unique especially during sun-up or sun-down..
From there proceed to the Fishriver Canyon Camping in Ai-Ais) maybe for to days. On the way home maybe visit Augrabies falls (+/- 120km east from Upington.
Please remember that the distances to drive between towns or places are quite large and on gravel roads extra caution and time is required for travelling.
If you see chance to spend an additional 3 or 4days in Namibia, consider also a vist to ETOSHA pan , however the distance from Windhoek north and back south again to Swakopmund is considerable.
I hope you will enjoy the trip tremendously.