The swap tool keeps track of everything for you. The tickets, dibs, etc. will make more sense once trading starts. They don't have anything to do with how many items you have put on the swap trading list.
With a multiplier of 1, on the first day of the swap you'll get 1 ticket. You can use it to put dibs on 1 item from the trade list. On the second day, you'll get 2 tickets, and so forth. You get extra tickets if people claim items from your list. The tickets add up! By the end of 10 days, the system will have given you 1+2+3+4+5+6+7+8+9+10 tickets -- that's 55 items you could potentially claim from the trade list, not counting additional dibs/tickets you've earned by having other people claim items you're offering.
If I used a multiplier of 2, you'd get 2 tickets on the first day, 4 on the second day, six on the third day, and so forth. I like a multiplier of 1. It gets off to a slow start, yes, but everybody has a chance at getting varieties where only 1 or 2 packets are being offered.
It's useful to look at the swap list now and then before trading begins. It's like browsing through a seed catalog -- you can read descriptions, look up varieties in the database, think about your garden plans. When you come across something you'd like to have, you can click the little treasure box icon, and that item will be in your wish list.
It's important to note that your wish list is NOT the same as calling dibs on something. It's not yours until you've "dibsed" it once trading has begun. The system will not automatically place dibs for you when something is on your wish list -- but you can look at your wish list to prioritize what you want to spend those precious first few tickets on.
Yes, claiming an item is "first come first served." Who gets the item depends only on who claims it first. If 5 packets are offered, 5 people will be able to claim those seeds. It has nothing to do with your wish list. Your wish list just helps you organize your thoughts on what you want and how badly you want it. The number of stars determines where an item is on your wish list... 5 star items will be at the top of your list, so you'll know to try for them first.
This turned into a long post about dibs and wish lists and tickets and trading, so I hope I didn't make it seem complicated. It will make sense as we go along, truly it willl. You have literally MONTHS to get comfortable with the swap tool before our swap starts.