Welcome to Tapas!
Especially if it’s your first comic, a lot of readers will have to be brought in by self promotion~ That’s basically where you take the time to post about and advertise your comic around different places, like social media, reddit, these forums, word of mouth irl, etc. Otherwise if the hosting site (like Tapas, in this case) likes your comic and promotes it, you can get lots of subscribers as well. But that’s the exception, not the norm. Most of us have to self promote :>
There are any number of ways to start a comic, but I think the most important thing (especially for a slice of life) is to make sure to introduce us to and get us acquainted with the main character. How you do so is up to you.
There tends not to be a hard and fast rule for best day/time to post, in fact it ends up not mattering much. The pros to posting on the weekend is that there’s more traffic on the site, but the con is that lots of people post then so your comic often won’t linger on the “Fresh” section very long. On the flip side, mid-week there are generally less people on reading comics, but your comic will linger in fresh for a longer time as there are generally less people posting, so it all kinda equals out in the end. I’ve done some posting different days of the week (I typically upload Sundays, but I’ve tried a Wednesday, and misc. days for Holiday Specials) and typically my comic performs the same regardless of the day. Time of day also mostly doesn’t matter, because there are readers all over the globe, and so no matter when you upload, it’ll be a good time for some people and bad for others.
For extra tips… just try to find a schedule that works for you, and have fun! Can’t wait to see your comic~