Anal experiments.

If for you - this will be the first experience, then the fingers will be enough. No need to immediately try to stick your arm up to your elbow. Pay attention to the area around the anus. Gently stroking with your fingers, you can lightly press on the sphincter. Such manipulations can already cause strong excitement. Look for hotspots and explore yourself. Also, relax completely. Clear your head and have fun. Enter with your fingers carefully and take care of the lubrication. Movement should be easy and painless. You need to play with the pace and accelerate when you are completely used to the new sensations.