Yes — this is already a very complete starter kit, especially for landscapes and close-up nature work.

Best uses from your set:

• 10-18mm: landscapes and ultra-wide scenes
• 18-55mm: general everyday photography
• 55-250mm: telephoto reach for distant subjects in good light
• 90mm macro: excellent for flowers, insects, and butterfly close-ups
• 8mm fisheye: a specialist creative lens, but not a main lens for most subjects

For your interests, the 10-18mm and 18-55mm cover landscapes well, and the 90mm macro is the standout choice for butterflies and other close subjects. The 55-250mm can also help when you need more distance.

A longer lens than 250mm is usually more useful for birds or moon shots than for general shooting. Teleconverters/extenders are not something you need to rush into; for butterfly work they can be less practical than simply learning your current lenses first.

The main advice from the community is: stop buying for now and spend time using this kit. After some real shooting, you’ll know what focal length or feature you actually miss. If anything, an external flash could be a more useful next accessory than another lens.