Hi Olivia,
Fingering and tampon insertion are completely different things, never clump the 2 of them together.
For tampons buy the slim/junior brand, I've always found you need to try different brands to see which ones you like better as they are different. Now that you have the tampon you will want to slightly bend your knees/squat, this will cause your vaginal canal to open enough to make a tampon slide in easier. If you have pain the tampon is either to big or just try again, there should be no pain. Just remember the slight squat will make it easier. Do not practice unless if you use some lubrication inside your vagina as when you have your period you are moister inside than normal due to the blood which is why tampon insertion should be easy.
Hope this helps
Hey no problems. Enjoy yourself in Spain. Is it for a swim meet or time at the ocean?
Good luck then!