okay so I recently discovered that I have wavy hair and that it isn't just really frizzy, I've started doing a routine every now and then but it only lasts about a day before i brush it out because idk what to do with it

so the picture above is my most recent routine, what I did was 2 rounds of OGX argan oil shampoo (I think) and then I put my head upside down and put in the matching brand conditioner and scrunched, let that sit for 2 minutes then rinsed and scrunched

After I got out of the shower I just lightly dabbed my hair with a towel and put on some creightons frizz no more blow dry cream (I thought I was gonna diffuse but my hair dryer was acting up so i didn't) and pantene thirsty ends quencher serum, then I just put it in a bonnet and went to bed

oh and I should mention I have really thick hair and it hasn't been cut in months, so the ends are kinda dead. I'm getting my hair thinned and trimmed on Tuesday

so I have questions..:

\- What products should I use to begin with? I don't own any right now I just use whatever my mum has lying around the house..so whatever products you guys think would be good (I'm uk/ireland area if that helps for specific products)

\- how do I maintain it after day 1, usually I just brush it out because it gets frizzy but I want to stop it from going bad like that

\- how do I style my hair down...? I never wear my hair down and I haven't since I was 8 so I kinda have no idea how to wear my hair down without it getting in my face or just looking stupid 

\- what's better? bonnet or plopping with the shirt?

okay thats all the questions I could think of rn but any advice is great, I have no clue what I'm doing but it seems to be doing alright just a little frizzy 

Need ALOT of help with my hair routine and stuff