Your next step is to make a business plan
List out your costs, annually for the next five hours. Factor in costs of some part time staff, all year or high season only.
Decide the cost of your time and how much time you would devote to this.
Then work out how the margin on the kind of books you would want to sell, then how many of those you would need to sell each year, in order to break even.
Then estimate the turnover you need during the high season months, to break even over the whole year, for the next five years.
What do you expect to happen to your costs and turnover, over the next five years ? Go up, or down ? Factor that into how much you need to turn over
There will be a lot of guesses here but it should give you a first cut sign of how feasible it is to cover your costs. If you need to sell one book a day, I'd say go for it. If you need to sell two hundred books a week, it might be a vanity project, you would be paying out money to 'play book shop'
What could you do to increase your turnover? Bookgroup's you already have. Is the space large enough to be attractive to poets or painters or writers who might like to use the space out of hours.
Next step would be to check your assumptions on what things will actually cost. What contingency you need in the budget? Would the person with the 'other' bookshop be interested in any kind of partnership to reduce your costs. Say sharing an accountant ? Would they be prepared to 'open the books' to you to validate your estimates of cost and turnover revenue. What other tips might they suggest. Could you try working there for a while to learn the ropes?
What other resources are there around you. Photographers prepared to let you use their pictures in your marketing I'm getting for a credit / display space. Students or even people at school who might want a job to keep the place open, do some marketing for you on social media.
What alternative uses might there be for the venue? Library, tourist info office, community centre. Covid might make more people want an alternative to WFH
There, some ideas to get you started. All the best.