Skeet's most often shot with 9s, but 8s will work. Trapshooters use up lots of oxygen debating the merits of 7 1/2 shot versus 8s for 16 yard shooting. Everyone uses 7 1/2s for long handicap.
The loads you have may work, but oft the pellets are too big for the range and often the loads are heavier than needed. The heaviest load I'd use would be a 1 1/8 oz load, and my reloaders are set up for 7/8 oz.
For starting out,I recommend the lightest loads you can find, especially if you're using a field gun. These run lighter than clays guns,and kick is exacerbated.
If you can find 1 oz Value packs at your local chain store, they give a lot of performance for the money. Mostly though, they're 1 1/8 oz and a tough heavy for high volume shooting.
Have fun, be safe, and enjoy....