I was there April 10 and vowed I'd try March next year, hoping for a bit cooler weather.
I'm an WDW vlogger addict so I had watched a ton of videos of youtube vloggers there on opening day especially, to get a feel for which booths and foods I wanted to try, see the year's merch, etc. That would be tip #1 is to look some of those up just to get a feel for the festival.
The topiaries are all over the place and fun to see. They start at the front entrance, with another set over by the Land and Imagination pavilions, some large ones on the entrance towards World Showcase, and then around in every country. Don't miss popping inside World ShowPlace for some AC time (with live entertainment and more food booths). They didn't have any merchandise booths inside this time, however.
There's always a scavenger hunt running, last few years its been Spike the Bee, and you get a prize. This year they started with plates but by the time I was there, they were out and had switched to travel mugs with orange bird, Figment, Spike, or Minnie on them. When I bought mine ($7.95) the CM asked if I'd like to just have my prize up front! It's fun to try and find him in all the different pavilions.
There is also a tiny hunt in the UK pavilion at the Twinings Tea shop that takes a few minutes and your prize is a couple of Twinings Tea options, including the cold brew ones you can just drop in your water bottle and enjoy.
I do carry a water bottle that keeps ice for days so I only have to refill the water and it stays frigid. I also like to bring my own reusable (not paper) straw and utensils to the festivals, as well as a lightweight & waterproof picnic "blanket" that packs into a tiny pouch in case I need to sit on the ground or wet grass, etc. Depending on how busy things are, this can come in handy. All of the above fit easily into my little (
Loungefly sized) backpack.
Another tip: buy a gift card that you wear around your wrist. They make cute ones for each festival (mine had Figment on it this year). You can preload $$ and pay quickly without having to reach for your wallet each time.
Be sure and check out the Epcot Experience in the old Horizons building to see all the plans for the park that are in the works. (Plus, more AC). If you're sensing a theme here . . . always build in time to cool off and drink water.
Weekends are always busier and you should have a much nicer time on your Monday and Thursday. The hours right at park opening and the two hours before the park closes are always lighter crowds.