In this talk I will present my latest work developed during my PhD on retrievals of exoplanet atmospheres from space-based Hubble Space Telescope (HST) and James Webb Space Telescope (JWST) transmission spectra. I will talk about our main findings, which include degeneracies between retrieved parameters (H2O abundance, temperature, and cloud-top pressure) and how these retrieved parameters strongly depend on model properties and on data reduction pipelines. I will also cover part of my work being currently developed at Lund University on the analysis of possible exocomet features in HARPS data from a young planetary system, establishing a link between the study of exoplanet structure and formation. I also aim to highlight some of the additional studies being done at the Exoplanets group at Lund University.