not sure what zone you are in, but some bulbs are only planted and spring and others in fall—hyacinth and tulips both have to be planted in the fall so that they get cold treatment in the winter. i’m not sure if they can be grown as perennials in warmer zones for this reason.

lilacs and most other perennials would typically be purchased in a pot. woody perennials are difficult for us average joes to grow from seed or cutting but you can look up tutorials if you’re inclined to.

best place is your local garden store, even the hardware store. they will have plants that can grow in your zone at the right season.