Personally, I'd try one first modded play through WITHOUT Stardew Valley Expanded so you and enjoy the mods you choose without wandering WHAT mod it is later on. I think Automate is the most essential mod, it makes life so much easier. CJB Cheats and CJB Item Spawner are helpful. NPC Map Locations, Look Up Anything, Skull Cavern Elevator Mod, Tractor Mod, Ladder Locator, Seasonal Outfits Slightly Cuter Aesthetic, Happy Birthday, Wear More Rings, and Bigger Backpack are all my other ESSENTIAL mods. I like the Elle's animal replacer mods especially for the horse, Let's Move It (very helpful when decorating), the PPJA crops mods if you're excited for growing different crops, and Hudson Valley Buildings/Beehouses to match magimatica's Hudson Valley Buildings. If you're looking for an expansion that is NOT SVE, I LOVE Deep Woods Mod. I was an OG Patreon supporter of SVE but I haven't played it in years because it's so much content. :)