The "kit" lens that came with your α7-series camera is a solid all-around performer. When you're ready to start branching out and expanding your photography horizons, you'll want to build on that kit-lens foundation. The Phoblographer suggests some of their favorite choices among the current lineup of full-frame (FE) primes and zooms. With an emphasis on value propositions, the Phoblographer's suggested upgrades won't break the bank as they boost your creative options.
Listed in the Phoblographer's article:
Sony FE 50mm F1.8 (link to Phoblographer's review)
Sony Sonnar T* FE 35mm f/2.8 ZA (link to Phoblographer's review)
Sony 16-35mm Vario-Tessar T FE F4 ZA OSS (link to Phoblographer's review)
Sony FE 70-200mm f/4 G OSS (link to Phoblographer's review)