DIY ! (home edition)

Sealer paint acts as a protective barrier, preparing porous surfaces like old walls or damp bathrooms to receive a top coat of paint by preventing moisture, stains, and chalkiness from affecting the new finish.It helps improve adhesion for new paint, fills minor cracks and holes, and ensures a more consistent and durable finish by creating a non-po... See more

Use white vinegar to kill mold, then follow up with commercial mold cleaning agent.

As for mold cleaner, I am very impressed by Magiclean's mold remover.

If it’s your first time definitely take your time with taping trim but practice making your cutting skills more refined try your best not to get paint on the tape anyway.

Cut your corner and edges before rolling.

Fill all the holes and fix anything with the drywall. Sand for better bonding. Make sure your walls are clean, get some TSP and wash those fuckers after you sand.

To clean them, you can use a mixture of baking soda and vinegar for mineral stains, or a commercial mold and mildew remover for mold growth. It's important to address the source of the moisture, such as improving ventilation or fixing leaks, to prevent stains from returning.

While painting over mould may temporarily disguise the problem, paint alone will not kill mould. Instead, the mould will continue to grow underneath the paint until it begins to show through. It may also cause the paint to bubble or flake, ruining the finish. If possible, it's best to remove the mould before painting.