With the advent of upcoming surveys such as DESI (already in the data collection and analysis phase, with Year 1 results published and soon to be public) and Euclid (successfully launched and collecting data), cosmology stands on the brink of new discoveries facilitated by the wealth of pristine galaxy sky distribution maps. To capitalize on the value of this data, we need equally excellent and precise predictions from our theoretical framework. Presently, the canonical LCDM cosmological model remains robust, yet to definitively unearth any deviations or signatures of new physics, we need to have an exquisitely accurate theoretical prediction of this model. With this objective in mind, we propose substantial development of the current perturbation theory-based analysis, first extending the one-loop power spectrum to two-loops. This will enhance both the accuracy and scale coverage of our utilization of existing data. Furthermore, within the same modelling framework, we intend to incorporate a one-loop bispectrum analysis, which will be compared and benchmarked against the established predictions in the field. This project is particularly timely in light of the recent computational breakthrough achieved by the Principal Investigator (PI) and collaborators, culminating in the development of a novel computational framework dubbed COBRA (Optimal Factorization of Cosmological Observables), accepted in the PRL. This innovation enables unprecedentedly efficient and rapid evaluation of higher-order loop integrals characteristic to cosmological perturbation theory, significantly enhancing the feasibility of applying comprehensive first principle theoretical model predictions to data analysis and thereby maximizing the utility of these surveys.