Laptop upgrade advice? RAM and SSD?

I'm looking at upgrading my current laptop to a gaming laptop. I don't play many massive triple A titles on it but I have a lot of games and keep a lot of stuff on it and sometimes my laptop struggles to load some stuff or it gets stutters and bits of lag. It's pretty old now, so I've been thinking of upgrading memory, processor and graphics. I heard SSD was faster to read files, but because I keep all my stuff on my laptop and I use it for video editing as well, I need HDD for storage. I thought about getting both HDD and SSD but to keep it close to my ideal price (£1000 and below, max. cap £1200) all the ones I can see are offering 6GB RAM. What level of SSD would I need to deal with the 2GB drop in RAM? Is it worth it?

Current specs: 8GB RAM, Intel i5 (aiming for i7), Intel HD Graphics (aiming for Nvidia GeForce GTX1060Ti), 1TB HDD

I did also question if having a low level graphics card would be the cause of some of these lag and loading problems too. Could upgrading just that fix things?

Thanks in advance for any help