Answer: Your hosta should do fine in a soil-less potting mix formulated for container plants. The larger the container you use, the better. The soil should be kept evenly moist but not sopping wet or saturated.
I am not sure your plan to keep it in a container will work year round. The reason I say this is that it is difficult to overwinter perennials in containers. The roots are not as well insulated in a container as they would be if planted in the ground. If possible it would be better to plant your hosta in the ground in the fall.
Otherwise you might try storing it for the winter. In late fall bring it into a dark cool place such as an unheated garage and keep the soil barely damp. In early spring, take it back outside again to wake up naturally with the season.
Slugs can attack hostas, yes. You can handpick them at night and drop them into soapy water, or you can use one of the slug baits based on iron phosphate.
Good luck with your hosta!
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