You might want to try Affinity Photo; it's an affordable ($49.99 single time purchase) alternative to Photoshop if you can't access Photoshop for one reason or another. It doesn't have quite all the the things Photoshop has, but it's very similar if you're familiar with Photoshop. Comes with a week trial if you want to test it out first. There's plenty of videos and tutorials online to get you more familiar fast, too.