If you struggle with applying basic Tajweed rules, in particular the “clear errors” (اللحن الجلي) which are errors you must correct, you should prioritise improving your Tajweed before your Hifdh, as it’s important that you memorise verses correctly.
The solution lies in learning from a skilled Qur’an teacher to master Tajweed. If you are not proficient in applying the essential Tajweed rules, then you must memorise with a teacher so they can correct your errors.
Correct recitation beautifies your recitation and enhances understanding, reflection, and humility during recitation. Tajweed is considered obligatory by some scholars.
Tip: Tajweed can also aid in memorising in some cases. For example, “أن يَجْعَلَ” is pronounced “ayy yaj’ala” when applying the Idghaam rule rather than “an yaj’ala”. The article “أن” (”an”) comes frequently in the Quran, so memorising the word as “ayy” helps you remember the next word starts with ي.